Linux AX25-HOWTO, Amateur Radio. Terry Dawson, VK2KTJ, terry@perf.no.itg.telecom.com.au v1.0 25 Apr 1996 The Linux Operating System is perhaps the only operating system in the world that can boast native and standard support for the AX.25 packet radio protocol utilised by Amateur Radio Operators worldwide. This document aims to describe how to install and configure this support. 1. Introduction. This document was originally an appendix to the HAM-HOWTO, but grew too large to be reasonably managed in that fashion. This document describes how to install and configure the native AX.25 and NetRom support for Linux. A few typical configurations are described that could be used as models to work from. 1.1. Changes from the previous version Additions: everything. Corrections/Updates: 1.2. Other related documentation. There is a lot of related documentation. There are many documents that relate to Linux networking in more general ways and I strongly recommend you also read these as they will assist you in your efforts and provide you with stronger insight into other possible configurations. They are: The HAM-HOWTO the Net-2-HOWTO the Ethernet-HOWTO the IPX-HOWTO and the Firewall-HOWTO 2. Where to obtain new versions of this document. The best place to obtain the latest version of this document is from a Linux Documentation Project archive. The Linux Documentation Project runs a Web Server and this document appears there as The AX25-HOWTO . You can always contact me, but I pass new versions of the document directly to the LDP HOWTO coordinator, so if it isn't there then chances are I haven't finished it. 3. Linux and the AX.25 and NetRom Packet Radio Protocols. The AX.25 protocol offers both connected and connectionless modes of operation, and is used either by itself for point-point links, or to carry other protocols such as TCP/IP and NetRom. It is similar to X.25 level 2 in structure, with some extensions to make it more useful in the amateur radio environment. The NetRom protocol is an attempt at a full network protocol and uses AX.25 at its lowest layer as a datalink protocol. It provides a network layer that is an adapted form of AX.25. Alan Cox developed some early kernel based AX.25 software support for Linux. Jonathon Naylor has taken up ongoing development of the code, has added NetRom support and is now the developer of the AX.25 related kernel code and utilities. DAMA support was developed by Joerg, DL1BKE. The Linux code supports KISS based TNC's (Terminal Node Controllers), the Ottawa PI card, the Gracilis PacketTwin card and other Z8530 SCC based cards with the generic SCC driver. The User programs contain a simple PMS (Personal Message System), a beacon facility, a line mode connect program, `listen' an example of how to capture all AX.25 frames at raw interface level and programs to configure the NetRom protocol. Included also are an AX.25 server style program to handle and despatch incoming AX.25 connections and a NetRom daemon which does most of the hard work for NetRom support. 4. The AX.25/NetRom software components. The AX.25 software is comprised of three components, the kernel source, the network configuration tools and the utility programs. The version 1.3.xx Linux kernels include the AX.25, NetRom, Z8530 SCC, PI card and PacketTwin drivers by default. I recommend you obtain and use the version 1.3.xx kernel source. These are three reasons I'm recommending you use the alpha version software even though most everyone else will recommend you don't use it: · it makes the process of building and configuring the software a whole lot simpler. There are no patches to apply it is a simple matter of configuring and compiling a kernel with the appropriate options enabled. · it is the most recent software and is most likely to provide the most satisfactory results. · like all new software, it needs testing and bug reports. The more people that take the software and attempt to use it in their own configurations the more likely it will be that bugs are uncovered and the easier it will be to get the software debugged. Join the team, contribute bug reports and help everybody. Be warned though, this software is alpha and may have problem that you wouldn't otherwise encounter. Please take all the usual precautions and be sure to keep a working kernel as backup when testing new kernels. It is wise to test a new kernel by booting from it from floppy before actually installing it with lilo, though I haven't bothered for about 90 kernels revisions so I'm fairly confident you can pretty safely run with alpha kernels. 4.1. Finding the kernel, tools and utility packages. 4.1.1. The kernel source: The kernel source can be found in its usual place at: ftp.funet.fi /pub/Linux/PEOPLE/Linus/v1.3/ 4.1.2. The network tools: Not all of the changes to the AX.25 software have made it into all related software packages yet. While the kernel now comes standard with AX.25 and NetRom support the standard net-tools package doesn't yet support NetRom properly. Jonathon Naylor has made a package that does support it available until Bernd can put the modifications into the standard release. If you intend to use the NetRom protocol then the special net-tools package that supports NetRom can be found at: ftp.ucsd.edu /hamradio/packet/tcpip/incoming/net-tools-1.1.95d.tar.gz If you don't want to use NetRom then I strongly recommend you stick to the latest release of the standard net-tools package which can be found at: ftp.inka.de /pub/comp/Linux/networking/net-tools/ or: ftp.linux.org.uk /pub/linux/Networking/PROGRAMS/NetTools/ The latest ipfwadm package can be found at: ftp.xos.nl /pub/linux/ipfwadm/ 4.1.3. The AX25 utilities: The AX.25 utility programs can be found at: sunsite.unc.edu /pub/Linux/apps/ham/ax25-utils-1.3.91a.tar.gz or: ftp.ucsd.edu /hamradio/packet/tcpip/incoming/ax25-utils-1.3.91a.tar.gz 5. Installing the AX.25/NetRom software. To successfully install AX.25 support on your linux system you must configure and install an appropriate kernel and then install the AX.25 utilities. 5.1. Compiling the kernel. If you are already familiar with the process of compiling the Linux Kernel then you can skip this section, just be sure to select the appropriate options when compiling the kernel. If you are not, then read on. The normal place for the kernel source to be unpacked to is the /usr/src directory into a subdirectory called linux. To do this you should be logged in as root and execute a series of commands similar to the following: # mv linux linux.old # cd /usr/src # gzip -dc linux-1.3.93.tar.gz | tar xvofp - # cd linux After you have unpacked the kernel source into place you need to run the configuration script and choose the options that suit your hardware configuration and the options that you wish built into your kernel. You do this by using the command: # make config You might also try: # make menuconfig if you prefer a full screen menu based method. I'm going to describe the original method, but you use whichever you are most comfortable with. In either case you will be offered a range of options at which you must answer `Y' or `N'. (Note you may also answer `M' if you are using modules. For the sake of simplicity I will assume you are not, please make appropriate modifications if you are). The options most relevant to an AX.25 configuration are: Networking support (CONFIG_NET) [Y/n/?] Y Loopback device support (CONFIG_BLK_DEV_LOOP) [N/y/m/?] Y Network firewalls (CONFIG_FIREWALL) [N/y/?] TCP/IP networking (CONFIG_INET) [Y/n/?] Y IP: forwarding/gatewaying (CONFIG_IP_FORWARD) [N/y/?] IP: firewalling (CONFIG_IP_FIREWALL) [N/y/?] (NEW) IP: tunneling (CONFIG_NET_IPIP) [N/y/m/?] (NEW) Amateur Radio AX.25 Level 2 (CONFIG_AX25) [N/y/?] Y AX.25 over Ethernet (CONFIG_BPQETHER) [N/y/?] (NEW) Amateur Radio NET/ROM (CONFIG_NETROM) [N/y/?] (NEW) Kernel/User network link driver(ALPHA) (CONFIG_NETLINK) [N/y/?] Network device support (CONFIG_NETDEVICES) [Y/n/?] Y SLIP (serial line) support (CONFIG_SLIP) [N/y/m/?] Z8530 SCC kiss emulation driver for AX.25 (CONFIG_SCC) [N/y/m/?] Other ISA cards (CONFIG_NET_ISA) [N/y/?] Ottawa PI and PI/2 support (CONFIG_PI) [N/y/?] (NEW) Gracilis PackeTwin support (CONFIG_PT) [N/y/?] (NEW) Standard/generic serial support (CONFIG_SERIAL) [Y/n/?] The options I have flagged with a `Y' are those that you must must answer `Y' to. The rest are dependent on what hardware you have and what options you want to include. Some of these options are described in more detail later on, so if you don't know what you want yet, then read ahead and come back to this step later. After you have completed the kernel configuration you should be able to cleanly compile your new kernel: # make dep # make clean # make zImage Make sure you move your arch/i386/boot/zImage file wherever you want it and then run lilo to ensure that you actually boot from it. 5.2. The network configuration tools. After you have compiled the kernel you should compile the new network configuration tools. These tools allow you to modify the configuration of network devices and to add routes to the routing table. The new release of the standard net-tools package includes support for AX.25 by the NetRom support isn't yet complete. Jonathon Naylor has produced an interim package which you should use if you intend to use the NetRom protocol, otherwise stick to the standard release. 5.2.1. Building the `Special' net-tools release I built Jonathons special release of net-tools with the following commands: # cd /usr/src # tar xvfz net-tools-1.1.95d.tar.gz # cd net-tools-1.1.95d There are a couple of things you now need to do. Firstly, the ipfw no longer works with new kernels, it has been replaced by the ipfwadm command described below. Trying to compile it will result in errors so you should edit the Makefile and place a `#' character before `ipfw' in the line beginning with `PROGS' as illustrated: PROGS = ifconfig hostname arp netstat route slattach rarp plipconfig dnsdomainname #ipfw Now you can enter: # make At this stage you will be prompted with a series of simple questions to answer. Make sure you answer `Y' to AX.25 and NetRom support and also to Ethernet, SLIP and PPP if you need them. After answering the questions the software will begin to compile. I compiled the tools with the 1.3.93 kernel source online and ran across the following error in a number of different files: In file included from slip.c:26: /usr/include/linux/if_arp.h:119: `MAX_ADDR_LEN' undeclared here (not in a functi on) I solved this by modifying each of the files listed, in this case lib/slip.c, as follows: replace: #include with: #include #include You should make this modification for each of these files, all in the lib subdirectory: ax25.c ether.c netrom.c slip.c and also these files in the top level directory: arp.c ifconfig.c rarp.c Newer kernels, or newer net-tools may not require this, so it is probably wise to try without modifying first. When the compilation is complete, you should need only use the: # make install command to install the programs in their proper place. 5.2.2. Building the standard net-tools release. Don't forget to read the Release file and follow any instructions there. The steps I used to compile the tools were: # cd /usr/src # tar xvfz net-tools-1.3.50-BETA6f.tar.gz # cd net-tools-1.3.50-BETA6f # make At this stage you will be presented with a series of configuration questions, similar to the kernel configuration questions. Be sure to include support for all of the protocols and network devices types that you intend to use. If you do not know how to answer a particular question then answer `Y'. The first question relates to NLS (National Language Support). I do not use this, and it will always be safe to answer `N' to, but if you require it then include it. I compiled the tools with the 1.3.93 kernel source online and ran across the following error in a number of different files: In file included from slip.c:26: /usr/include/linux/if_arp.h:119: `MAX_ADDR_LEN' undeclared here (not in a function) I solved this by modifying each of the files listed, in this case lib/slip.c, as follows: replace: #include with: #include #include You should make this modification for each of these files, all in the lib subdirectory: arcnet.c ax25.c ether.c netrom.c netrom_rt.c ppp.c slip.c tr.c tunnel.c and also these files in the top level directory: arp.c ifconfig.c rarp.c Newer kernels, or newer net-tools may not require this, so it is probably wise to try without modifying first. When the compilation is complete, you should need only use the: # make install command to install the programs in their proper place. If you wish to use the IP firewall facilities then you will need the latest firewall administration tool ipfwadm. This tool replaces the older ipfw tool which will not work with new kernels. I compiled the ipfwadm utility with the following commands: # cd /usr/src # tar xvfz ipfwadm-2.0beta2.tar.gz # cd ipfwadm-2.0beta2 # make install # cp ipfwadm.8 /usr/man/man8 # cp ipfw.4 /usr/man/man4 5.3. The AX.25 user programs. After you have successfully compiled and booted your new kernel, you need to compile the user programs. To compile and install the user programs you should use a series of commands similar to the following: # cd /usr/local # gzip -dc ax25-utils-1.3.91a.tar.gz | tar xvvof - # cd ax25-utils-1.3.91a # make install The files will be installed under the /usr/local directory by default in subdirectories: bin, sbin, etc and man. 6. Configuring a RAW AX.25 connected mode interface. The first stage to configuration of an AX.25 interface is to configure it to work as a `vanilla' AX.25 interface with no TCP/IP. There are two distinct parts to the configuration, configuring to allow outgoing connections and configuring to accepting incoming connections. They are described in turn. 6.1. Configuring to allow outgoing connections. The AX.25 software has been designed to work with a TNC in kiss mode or an Ottawa PI2 card/PacketTwin card. If you are using a KISS TNC then you will need to create the AX.25 interface as it will not already exist. Creating an AX.25 port is very similar to creating a slip device. You will need to have the TNC preconfigured and connected to your serial port. You can use a comms program like minicom or seyon to configure the TNC into kiss mode if you wish. You use the axattach program in much the same way as you would use the slattach program (refer to the NET-2-HOWTO for more information on slattach and the other network software for Linux). For example: # /usr/local/sbin/axattach -s 4800 /dev/ttyS1 VK2KTJ-1 & # sleep 2 would configure your /dev/ttyS1 serial device to be a kiss interface at 4800 bps, with the hardware address VK2KTJ-1. The sleep of 2 seconds is necessary just to give the kernel a little time to do some housekeeping that it has to do before you try and change the interface. If you are using a PI or PacketTwin card then you should use the axsetcall command to change the callsign of the appropriate port to that which you intend to use. Refer to the PI/PacketTwin section for the names of the network devices to use. All this step has done is to actually activate the device in the kernel, you need to run other programs before you an actually make use of the port. The AX.25 ports have a configuration file that can be read by any program that wants to find information about an AX.25 port. This file is called the: /usr/local/etc/axports file. The format of the file is as follows: callsign baudrate window label where: callsign is the AX.25 callsign you want to assign to the port. baudrate is the speed at which you wish the port to communicate with your TNC. window is the AX.25 window (K) parameter. This is the same as the MAXFRAME setting of many tnc's. label is a name for the port. In my case, mine looks like: VK2KTJ-1 4800 1 radio Note that this file is line based, that is, the first entry is considered to describe `AX25 port 1' and the second line to describe `AX25 port 2'. Some of the application programs need this `port number'. At this stage not all of this information is used, it will be picked up and used in later developments. You now should be able to make outgoing AX.25 connections. To test AX.25 connected mode you could use the call program as demonstrated: /usr/local/bin/call VK2DAY via VK2SUT The call program is a linemode terminal program for making AX.25 calls. It recognises lines that start with `~' as command lines. The `~.' command will close the connection. Please refer to the man pages in /usr/local/man and the README file in ax25-utils-1.3.91a distribution for more information. 6.2. Configuring to accept incoming connections. Linux is a powerful operating system and offers a great deal of flexibility in how it is configured. With this flexibility comes a cost in configuring it to do what you want. When configuring your Linux machine to accept incoming AX.25 connections there are a number of questions you need to ask yourself. The most important of which is: "What do I want users to see when they connect?". As detailed in the software list at the start of this document there are BBS systems that are being developed that you might want users to see when they connect, alternatively you might want to give users a login prompt so that they can make use of a shell account, or you might even have written your own program, such as a customised database or a game, that you want people to connect to. Whatever you choose, you must tell the AX.25 software about this so that it knows what software to run when it accepts an incoming AX.25 connection. You do this within the /usr/local/etc/ax25d.conf. This file is the configuration file for the ax25d AX.25 daemon which handles incoming AX.25 connections. The file is a little cryptic looking at first, but you'll soon discover it is very simple in practice, with a small trap for you to be wary of. The format of the ax25d.conf file is as follows: # This is a comment and is ignored by the ax25d program. [] window T1 T2 T3 N2 window T1 T2 T3 N2 defaults window T1 T2 T3 N2 window T1 T2 T3 N2 default window T1 T2 T3 N2 Where: # at the start of a line marks a comment and is completely ignored by the ax25d program. is the AX.25 callsign of the interface that this particular paragraph is for. is the callsign of the peer node that this particular configuration applies to. If you don't specify an SSID here then any SSID will match. window is the AX.25 Windows parameter (K) or MAXFRAME parameter for this configuration. T1 is the Frame retransmission (T1) timer in half second units. T2 is the amount of time the AX.25 software will wait for another incoming frame before preparing a response in 1 second units. T3 is the amount of time of inactivity before the AX.25 software will disconnect the session in 1 second units. N2 is the number of consecutive retransmissions that will occur before the connection is closed. provides a mechanism for determining certain types of general permissions. The modes are enabled or disabled by setting or resetting bits in an 8 bit map. You set that map by setting to the sum of the following values: 1 Setup utmp, and run on a ptty (planned). 2 UNUSED. 4 UNUSED. 8 UNUSED. 16 UNUSED. 32 UNUSED. 64 Disallow digipeated uplinks, only allow direct connections. 128 Lockout, Barred, immediate disconnect. is the userid that the program to be run to support the connection should be run as. is the full pathname of the command to be run, with no arguments specified. is the text that should appear in a ps as the command name running (normally the same as except without the directory path information. are the command line argument to be passed to the <:cmd> when it is run. You pass useful information into these arguments by use of the following tokens: %U AX.25 callsign of the connected party without the SSID, in uppercase. %u AX.25 callsign of the connected party without the SSID, in lowercase. %S AX.25 callsign of the connected party with the SSID, in uppercase. %s AX.25 callsign of the connected party with the SSID, in lowercase. You need one section in the above format for each AX.25 interface you want to accept incoming AX.25 connections on. There are two special lines in the paragraph, one starts with the string `defaults' and other starts with the string `default' (yes there is a difference). These lines serve special functions. The `default' lines purpose should be obvious, this line acts as a catch-all, so that any incoming connection on the interface that doesn't have a specific rule will match the `default' rule. If you don't have a `default' rule, then any connections not matching any specific rule will be disconnected immediately without notice. The `defaults' line is a little more subtle, and here is the trap I mentioned earlier. In any of the fields for any definition for a peer you can use the `*' character to say `use the default value'. The `default' line is what sets those default values. The kernel software itself has some defaults which will be used if you don't specify any. The trap is that the these defaults apply only to those rules below the `default' line not to those above. You may have more than one `default' rule per interface definition, and in this way you may create groups of default configurations. Ok, an illustrative example: # ax25d.conf for VK2KTJ - 21/11/95 # This configuration uses the AX.25 port defined earlier. [VK2KTJ-1] NOCALL * * * * * 0 guest /usr/games/fortune defaults 1 10 * * * 0 root /usr/local/sbin/axspawn axspawn %u + VK2XLZ-1 * * * * * * * * * VK2DAY-1 * * * * * * * * * default 1 10 5 100 5 0 root /usr/lbbs/bin/bbsrx bbsrx -s %u # This example says that anybody connecting to the interface on my machine with the callsign VK2KTJ-1 will have the following rules applied: Anyone whose callsign is set to `NOCALL' should use the kernel default parameters and have the fortune program run as guest for them. The defaults line changes two parameters from the kernel defaults (Window and T1) and will run the /usr/local/sbin/axspawn program for them. Any copies of /usr/local/sbin/axspawn run this way will appear as axspawn in a ps listing for convenience. The next two lines definitions for two stations who will receive those permissions. The last line in the paragraph is the `catch all' definition that everybody else will get (including VK2XLZ and VK2DAY using any other SSID other than -1). This definition sets all of the parameters implicitly and will cause the bbsrx program to run with a command line argument of the callsign of the connecting peer in lower case with no SSID. If you wanted to define rules for another interface, even a NetRom interface, then you would add another paragraph coded in the same way with rules and callsign appropriate to it. This example is a contrived one but I think it illustrates clearly the important features of the syntax of the configuration file. Jonathon includes a much longer and more detailed example in the ax25-utils package. 6.2.1. Configuring axspawn. The axspawn program is a simple program that allows AX.25 stations who connect to be log in to your machine. It is invoked from the ax25d program as described above. To allow a user to log in to your machine you should add a line similar to the following into your /usr/local/etc/ax25d.conf file: default * * * * * 1 root /usr/local/sbin/axspawn axspawn %u If the line ends in the + character then the connecting user must hit return before they will be allowed to login. The default is to not wait. Any individual host configurations that follow this line will have the axspawn program run when they connect. When axspawn is run it first checks that the command line argument it is supplied is a legal callsign, strips the SSID, then it checks that /etc/passwd file to see if that user has an account configured. If there is an account, and the password is either "" (null) or + then the user is logged in, if there is anything in the password field the user is prompted to enter a password. If there is not an existing account in the /etc/passwd file then axspawn may be configured to automatically create one. You can alter the behaviour of axspawn in various ways by use of the /usr/local/etc/axspawn.conf file. This file is formatted as follows: # /usr/local/etc/axspawn.conf # # allow automatic creation of user accounts create yes # # guest user if above is 'no' or everything else fails. Disable with "no" guest no # # group id or name for autoaccount group ax25 # # first user id to use first_uid 2001 # # maximum user id max_uid 3000 # # where to add the home directory for the new users home /home/ax25 # # user shell shell /bin/bash # # bind user id to callsign for outgoing connects. associate yes The eight configurable characteristics of axspawn are as follows: # indicates a comment. create if this field is set to yes then axspawn will attempt to automatically create a user account for any user who connects and does not already have an entry in the /etc/passwd file. guest this field names the login name of the account that will be used for people who connect who do not already have accounts if create is set to no. This is usually ax25 or guest. group this field names the group name that will be used for any users who connect and do not already have an entry in the /etc/passwd file. first_uid this is the number of the first userid that will be automatically created for new users. max_uid this is the maximum number that will be used for the userid of new users. home this is the home (login) directory of new users. shell this is the login shell of any new users. associate this flag indicates whether outgoing AX.25 connections made by this user after they login will use their own callsign, or your stations callsign. 7. Configuring an AX.25 interface for tcp/ip. It is very simple to configure an AX.25 port to carry tcp/ip. You need to use the ifconfig program to configure the ip address and netmask details for the port and add a route via the port, just as you would for any other tcp/ip interface. # /sbin/ifconfig sl0 44.136.8.5 # /sbin/ifconfig sl0 netmask 255.255.255.0 # /sbin/ifconfig sl0 broadcast 44.136.8.255 # /sbin/ifconfig sl0 arp mtu 256 up # /sbin/route add -net 44.136.8.0 sl0 # /sbin/route add default sl0 The commands listed above are typical of the sort of configuration many of you would be familiar with if you have used NOS or any of its derivatives or any other tcp/ip software. Note that the default route might not be required in your configuration if you have some other network device configured. To test it out, try a ping or a telnet to a local host. # ping -i 5 44.136.8.58 Note the use of the `-i 5' arguments to ping to tell it to send pings every 5 seconds instead of its default of 1 second. 8. Configuring an AX.25 interface for NetRom. To configure NetRom on an AX.25 interface you must configure two files. 8.1. Configuring /usr/local/etc/nrports The first is the /usr/local/etc/nrports file. This file describes the NetRom port. This file is formatted as follows: callsign alias description Where: callsign is the callsign that the NetRom traffic from this port will use. alias is the NetRom alias this port will have assigned to it. description is a free text description of the port. An example would look something like the following: VK2KTJ MTCOLAH NetRom Switch Port Note again that the first line refers to the first NetRom interface, the second line refers to the second NetRom interface and so on. 8.2. Configuring /usr/local/etc/nrbroadcast The second file is the /usr/local/etc/nrbroadcast file. This file is formatted as follows: port min_obs def_qual worst_qual verbose Where: port is the port number obtained from the /usr/local/etc/axports file. The first line in the file describes AX.25 port number one, the second describes port number two etc. If you do not have an entry in /usr/local/etc/nrbroadcasts for a port then this means that no NetRom routing will occur and any received NetRom broadcasts will be ignored for that port. min_obs is the minimum obselesence value for the port. def_qual is the default quality for the port. worst_qual is the worst quality value for the port, any routes under this quality will be ignored. verbose is a flag determining whether full NetRom routing broadcasts will occur from this port or only a routing broadcast advertising the node itself. An example would look something like the following: 1 1 200 10 1 2 1 200 10 1 8.3. Starting NetRom When you have the two configuration files completed you start NetRom with the command: # /usr/local/sbin/netromd You should then be able to make NetRom connections with the call program to NetRom hosts. 9. Configuring IP on a NetRom interface. Configuring a NetRom interface for tcp/ip is almost identical to configuring an AX.25 interface for tcp/ip. Again you use the ifconfig and route commands, but you need to manually add arp entries for hosts you wish to route to because there is no mechanism available for your machine to learn what NetRom address it should use to reach a particular IP host. So, to configure your nr0 for IP with an IP address of 44.136.8.5 and a callsign of VK2KTJ-1 you would use something like: # ifconfig nr0 44.136.8.5 hw netrom VK2KTJ-1 # route add 44.136.8.5 nr0 Then for each IP host you wish to reach via NetRom you need to set route and arp entries. To reach a destination host with an IP address of 44.136.80.4 at NetRom address BBS:VK3BBS via a NetRom neighbour with callsign VK2SUT-0 you would use commands as follows: # route add 44.136.80.4 nr0 # arp -t netrom -s 44.136.80.4 vk2sut-0 # nrparms -nodes vk3bbs + BBS 120 6 sl0 vk2sut-0 The `120' and `6' arguments to the nrparms command are the NetRom quality and obsolescence count values for the route. 10. Configuring an Ethernet device for AX.25 ala BPQ Linux support BPQ Ethernet compatibility. This enables you to run the AX.25 protocol over your Ethernet LAN and to interwork your linux machine with other BPQ machines on the LAN. Configuration is quite straightforward. You firstly must have configured a standard Ethernet device. This means you will have compiled your kernel to support your Ethernet card, and executed configuration commands similar to the following: # ifconfig eth0 44.136.8.5 netmask 255.255.255.248 up # ifconfig eth0 broadcast 44.136.8.103 # route add -net 44.136.8.96 netmask 255.255.255.248 eth0 To configure the BPQ support you need to associate an AX.25 callsign with your Ethernet hardware address. You should use the following: # axparms -dev eth0 vk2ktj-9 This says that AX.25 callsign vk2ktj-9 is associated with the eth0 device. BPQ Ethernet normally uses a multicast address. The Linux implementation does not, and instead it uses the normal Ethernet broadcast address. The NET.CFG file for the BPQ ODI driver should therefore look similar to this: LINK SUPPORT MAX STACKS 1 MAX BOARDS 1 LINK DRIVER E2000 ; or other MLID to suit your card INT 10 ; PORT 300 ; to suit your card FRAME ETHERNET_II PROTOCOL BPQ 8FF ETHERNET_II ; required for BPQ - can change PID BPQPARMS ; optional - only needed if you want ; to override the default target addr ETH_ADDR FF:FF:FF:FF:FF:FF ; Target address 11. Ottawa PI/PI2 card driver and Gracilis PacketTwin driver. The Ottawa PI and the Gracilis PacketTwin are Z8530 SCC based card for IBM PC type machines that are in common usage by Amateur Radio operators worldwide. The PI card supports a high speed half duplex (single DMA channel) port, and a low speed (<9k6bps interrupt driven) half duplex port. The PI2 is a new version of the card that supports an on board radio modem and improved hardware design. The PacketTwin card supports two high speed port and is capable of accepting on board modems. The PI card driver was written by David Perry, The PacketTwin card driver was written by Craig Small VK2XLZ, . Both drivers are a standard feature of the 1.3.xx kernel. Please refer to the AX.25 section above for details on how to configure the kernel to include the PI card or the PacketTwin card drivers. Once you have the appropriate driver configured into your kernel then you should reboot and when you do, you should see mention of the PI or PacketTwin card driver in the messages that appear on the screen while the kernel is booting. The drivers test each of the I/O port addresses that the card might be configured for and reports any that it finds. You should then look at the /proc/net/dev file and you should see reference to devices called pi0a and pi0b or pt0a and pt0b for the PI and PacketTwin cards respectively. If the devices don't appear then recheck that you have configured and compiled your kernel correctly and that you are in fact actually running your new kernel. If you still don't then this suggests that your PI or PacketTwin card was not detected by the kernel while it booted and may indicate that you have some sort of hardware conflicting with your PI/PT card that prevented it being detected. If all of the above went as planned then you will need to configure your PI/PT card for IP. The configuration of the PI/PT cards is virtually identical to that of any other IP interface. Something like the following should work ok for you: # /sbin/ifconfig pi0a 44.136.8.5 # /sbin/ifconfig pi0a netmask 255.255.255.0 # /sbin/ifconfig pi0a broadcast 44.136.8.255 # /sbin/ifconfig pi0a arp mtu 256 up # /sbin/route add -net 44.136.8.0 pi0a # /sbin/route add default pi0a Note that pi0a refers to the `a' port on the first PI card found, and that pi0b would therefore refer to the `b' port on the first PI card found. pt0a would therefore be the first port on the first PacketTwin card detected. As usual, when this has been done you can test the interface with the ping or telnet command to ensure it is working. 12. Z8530 SCC Kiss Emulation Joerg Reuter, DL1BKE has developed generic support for Z8530 SCC based cards. His driver is configurable to support a range of different types of cards and present an interface that looks like a KISS TNC so you can treat it as though it were a KISS TNC. 12.1. Obtaining and building the configuration tool package. The kernel driver is included in the standard kernel distribution, but there are a suite of configuration tools that you will need to obtain as well. To compile the kernel support you must be sure to answer `Y' to: `Z8530 SCC kiss emulation driver for AX.25' when asked during a kernel `make config'. You can obtain the configuration tools package from: ftp.ucsd.edu /hamradio/packet/tcpip/incoming/z8530drv-2.0.dl1bke.real.tar.gz The following command were what I used to compile and install the package for kernel version 1.3.93: # cd /usr/src # gzip -dc z8530drv-2.0.dl1bke.real.tar.gz | tar xvpofz - # cd z8530drv # rm gencfg sccinit sccstat # make dep # make utils # make install Note: I've not followed the instructions included because the version of driver in the 1.3.93 kernel is actually newer than that included in the package and the normal installation process would have overwritten the new kernel source with the older version. After the above is complete you should have three new programs installed in your /sbin directory: gencfg, sccinit and sccstat. It is these programs that you will use to configure the driver for your card. You will also have a group of new special device files created in your /dev called scc0 .. scc7. These will be used later and will be the `KISS' devices you will end up using. 12.2. Configuring the driver for your card. The z8530 SCC driver has been designed to be as flexible as possible so as to support as many different types of cards as possible. With this flexibility has come some cost in configuration. There is more comprehensive documentation in the package and you should read this if you have any problems. You should particularly look at doc/scc_eng.doc or doc/scc_ger.doc for more detailed information. I've paraphrased the important details, but as a result there is a lot of lower level detail that I have not included. The main configuration file is read by the sccinit program and is called /etc/z8530drv.rc. This file is broken into two main stages: Configuration of the hardware parameters and channel configuration. After you have configured this file you need only add: # sccinit into the rc file that configures your network and the driver will be initialised according to the contents of the configuration file. You must do this before you attempt to use the driver. 12.2.1. Configuration of the hardware parameters. The first section is broken into stanzas, each stanza representing an 8530 chip. Each stanza is a list of keywords with arguments. You may specify up to four SCC chips in this file by default. The #define MAXSCC 4 in scc.c can be increased if you require support for more. The allowable keywords and arguments are: chip the chip keyword is used to separate stanzas. It will take anything as an argument. The arguments are not used. data_a this keyword is used to specify the address of the data port for the z8530 channel `A'. The argument is a hexadecimal number e.g. 0x300 ctrl_a this keyword is used to specify the address of the control port for the z8530 channel `A'. The arguments is a hexadecimal number e.g. 0x304 data_b this keyword is used to specify the address of the data port for the z8530 channel `B'. The argument is a hexadecimal number e.g. 0x301 ctrl_b this keyword is used to specify the address of the control port for the z8530 channel `B'. The arguments is a hexadecimal number e.g. 0x305 irq this keyword is used to specify the IRQ used by the 8530 SCC described in this stanza. The argument is an integer e.g. 5 pclock this keyword is used to specify the frequency of the clock at the PCLK pin of the 8530. The argument is an integer frequency in Hz which defaults to 4915200 if the keyword is not supplied. board the type of board supporting this 8530 SCC. The argument is a character string. The allowed values are: PA0HZP the PA0HZP SCC Card EAGLE the Eagle card PC100 the DRSI PC100 SCC card PRIMUS the PRIMUS-PC (DG9BL) card BAYCOM BayCom (U)SCC card escc this keyword is optional and is used to enable support for the Extended SCC chips (ESCC) such as the 8580, 85180, or the 85280. The argument is a character string with allowed values of `yes' or `no'. The default is `no'. vector this keyword is optional and specifies the address of the vector latch (also known as "intack port") for PA0HZP cards. There can be only one vector latch for all chips. The default is 0. special this keyword is optional and specifies the address of the special function register on several cards. The default is 0. option this keyword is optional and defaults to 0. Some example configurations for the more popular cards are as follows: BayCom USCC chip 1 data_a 0x300 ctrl_a 0x304 data_b 0x301 ctrl_b 0x305 irq 5 board BAYCOM # # SCC chip 2 # chip 2 data_a 0x302 ctrl_a 0x306 data_b 0x303 ctrl_b 0x307 board BAYCOM PA0HZP SCC card chip 1 data_a 0x153 data_b 0x151 ctrl_a 0x152 ctrl_b 0x150 irq 9 pclock 4915200 board PA0HZP vector 0x168 escc no # # # chip 2 data_a 0x157 data_b 0x155 ctrl_a 0x156 ctrl_b 0x154 irq 9 pclock 4915200 board PA0HZP vector 0x168 escc no DRSI SCC card chip 1 data_a 0x303 data_b 0x301 ctrl_a 0x302 ctrl_b 0x300 irq 7 pclock 4915200 board DRSI escc no If you already have a working configuration for your card under NOS, then you can use the gencfg command to convert the PE1CHL NOS driver commands into a form suitable for use in the z8530 driver configuration file. To use gencfg you simply invoke it with the same parameters as you used for the PE1CHL driver in NET/NOS. For example: # gencfg 2 0x150 4 2 0 1 0x168 9 4915200 will generate a skeleton configuration for the OptoSCC card. 12.2.2. Channel Configuration The Channel Configuration section is where you specify all of the other parameters associated with the port you are configuring. Again this section is broken into stanzas. One stanza represents one logical port, and therefore there would be two of these for each one of the hardware parameters stanzas as each 8530 SCC supports two ports. These keywords and arguments are also written to the /etc/z8530drv.rc file and must appear after the hardware parameters section. Sequence is very important in this section, but if you stick with the suggested sequence it should work ok. The keywords and arguments are: device this keyword must be the first line of a port definition and specifies the name of the special device file that the rest of the configuration applies to. e.g. /dev/scc0 speed this keyword specifies the speed in bits per second of the interface. The argument is an integer: e.g. 1200 clock this keyword specifies where the clock for the data will be sourced. Allowable values are: dpll normal halfduplex operation external MODEM supplies its own Rx/Tx clock divider use fullduplex divider if installed. mode this keyword specifies the data coding to be used. Allowable arguments are: nrzi or nrz rxbuffers this keyword specifies the number of receive buffers to allocate memory for. The argument is an integer, e.g. 8. txbuffers this keyword specifies the number of transmit buffers to allocate memory for. The argument is an integer, e.g. 8. bufsize this keyword specifies the size of the receive and transmit buffers. The arguments is in bytes and represents the total length of the frame, so it must also take into account the AX.25 headers and not just the length of the data field. This keyword is optional and default to 384 txdelay the KISS transmit delay value, the argument is an integer in mS. persist the KISS persist value, the argument is an integer. slot the KISS slot time value, the argument is an integer in mS. tail the KISS transmit tail value, the argument is an integer in mS. fulldup the KISS full duplex flag, the argument is an integer. 1==Full Duplex, 0==Half Duplex. wait the KISS wait value, the argument is an integer in mS. min the KISS min value, the argument is an integer in S. maxkey the KISS maximum keyup time, the argument is an integer in S. idle the KISS idle timer value, the argument is an integer in S. maxdef the KISS maxdef value, the argument is an integer. group the KISS group value, the argument is an integer. txoff the KISS txoff value, the argument is an integer in mS. softdcd the KISS softdcd value, the argument is an integer. slip the KISS slip flag, the argument is an integer. 12.3. Using the driver. To use the driver you simply treat the /dev/scc* devices just as you would a serial tty device with a KISS TNC connected to it. For example, to configure Linux Kernel networking to use your SCC card you could use something like: # axattach -s 4800 /dev/scc0 VK2KTJ You can also use NOS to attach to it in precisely the same way. From JNOS for example you would use something like: attach asy scc0 0 ax25 scc0 256 256 4800 12.4. The sccstat and sccparam tools. To assist in the diagnosis of problems you can use the sccstat program to display the current configuration of an SCC device. To use it try: # sccstat /dev/scc0 you will displayed a very large amount of information relating to the configuration and health of the /dev/scc0 SCC port. The sccparam command allows you to change or modify a configuration after you have booted. Its syntax is very similar to the NOS param command, so to set the txtail setting of a device to 100mS you would use: # sccparam /dev/scc0 txtail 0x8 13. HOWTO link NOS and the Linux kernel networking software Many people like to run some version of NOS under Linux because it has all of the features and facilities they are used to. Most of those people would also like to have the NOS running on their machine capable of talking to the Linux kernel so that they can offer some of the linux capabilities to radio users. 13.1. Linking NOS and Linux using a pipe device Brandon S. Allbery, KF8NH, contributed the following information to explain how to interconnect the NOS running on a Linux machine with the kernel code using the Linux pipe device. Since both Linux and NOS support the slip protocol it is possible to link the two together by creating a slip link. You could do this by using two serial ports with a loopback cable between them, but this would be slow and costly. Linux provides a feature that many other Unix-like operating systems provide called `pipes'. These are special pseudo devices that look like a standard tty device to software but in fact loopback to another pipe device. To use these pipes the first program must open the master end of the pipe, and the open then the second program can open the slave end of the pipe. When both ends are open the programs can communicate with each other simply by writing characters to the pipes in the way they would if they were terminal devices. To use this feature to connect the Linux Kernel and a copy of NOS, or some other program you first must choose a pipe device to use. You can find one by looking in your /dev directory. The master end of the pipes are named: ptyp[1-f] and the slave end of the pipes are known as: ttyp[1-f]. Remember they come in pairs, so if you select /dev/ptypf as your master end then you must use /dev/ttypf as the slave end. Once you have chosen a pipe device pair to use you should allocate the master end to you linux kernel and the slave end to the NOS program, as the Linux kernel starts first and the master end of the pipe must be opened first. You must also remember that your Linux kernel must have a different IP address to your NOS, so you will need to allocate a unique address for it if you haven't already. You configure the pipe just as if it were a serial device, so to create the slip link from your linux kernel you can use commands similar to the following: # /sbin/slattach -s 38400 -p slip /dev/ptypf & # /sbin/ifconfig sl0 broadcast 44.255.255.255 pointopoint 44.70.248.67 / mtu 1536 44.70.4.88 # /sbin/route add 44.70.248.67 sl0 # /sbin/route add -net 44.0.0.0 gw 44.70.248.67 In this example the Linux kernel has been given IP address 44.70.4.88 and the NOS program is using IP address 44.70.248.67. The route command in the last line simply tells your linux kernel to route all datagrams for the amprnet via the slip link created by the slattach command. Normally you would put these commands into your /etc/rc.d/rc.inet2 file after all your other network configuration is complete so that the slip link is created automatically when you reboot. Note: there is no advantage in using cslip instead of slip as it actually reduces performance because the link is only a virtual one and occurs fast enough that having to compress the headers first takes longer than transmitting the uncompressed datagram. To configure the NOS end of the link you could try the following: # you can call the interface anything you want; I use "linux" for convenience. attach asy ttypf - slip linux 1024 1024 38400 route addprivate 44.70.4.88 linux These commands will create a slip port named `linux' via the slave end of the pipe device pair to your linux kernel, and a route to it to make it work. When you have started NOS you should be able to ping and telnet to your NOS from your Linux machine and vice versa. If not, double check that you have made no mistakes especially that you have the addresses configured properly and have the pipe devices around the right way. 14. Some sample configurations. Following are examples of the most common types of configurations. These are guides only as there are as many ways of configuring your network as there are networks to configure, but they may give you a start. 14.1. Small Ethernet LAN with Linux as a router to Radio LAN Many of you may have small local area networks at home and want to connect the machines on that network to your local radio LAN. This is the type of configuration I use at home. I arranged to have a suitable block of addresses allocated to me that I could capture in a single route for convenience and I use these on my Ethernet LAN. Your local IP coordinator will assist you in doing this if you want to try it as well. The addresses for the Ethernet LAN form a subset of the radio LAN addresses. The following configuration is the actual one for my linux router on my network at home: . . . . . . --- . | Network /---------\ . Network | 44.136.8.96/29| | . 44.136.8/24 \ | / | | Linux | . \|/ | | | . | | eth0 | Router | . /-----\ /----------\ | |---------------| |-----| TNC |----| Radio |---/ | 44.136.8.97 | and | . \-----/ \----------/ | | | sl0 | | Server | 44.136.8.5 | | | . | | | . | \_________/ . --- . . . . . . #!/bin/sh # /etc/rc.net # This configuration provides one KISS based AX.25 port and one # Ethernet device. echo "/etc/rc.net" echo " Configuring:" echo -n " loopback:" /sbin/ifconfig lo 127.0.0.1 /sbin/route add 127.0.0.1 echo " done." echo -n " ethernet:" /sbin/ifconfig eth0 44.136.8.97 netmask 255.255.255.248 \ broadcast 44.136.8.103 up /sbin/route add 44.136.8.97 eth0 /sbin/route add -net 44.136.8.96 netmask 255.255.255.248 eth0 echo " done." echo -n " AX.25: " /usr/local/sbin/axattach -s 4800 /dev/ttyS1 VK2KTJ-0 & sleep 2 /sbin/ifconfig sl0 44.136.8.5 netmask 255.255.255.0 \ broadcast 44.136.8.255 mtu 512 up /sbin/route add 44.136.8.5 sl0 /sbin/route add -net 44.136.8.0 netmask 255.255.255.0 window 1024 sl0 echo " Routing:" /sbin/route add default gw 44.136.8.68 window 1024 sl0 echo " default route." echo done. # end · You must have IP_FORWARDING enabled in your kernel. · The AX.25 configuration files are pretty much those used as examples in the earlier sections, refer to those where necessary. · I've chosen to use an IP address for my radio port that is not within my home network block. I needn't have done so, I could have easily used 44.136.8.97 for that port too. · 44.136.8.68 is my local IPIP encapsulated gateway and hence is where I point my default route. · Each of the machines on my Ethernet network have a route: route add -net 44.0.0.0 gw 44.136.8.97 window 512 mss 512 eth0 The use of the mss and window parameters means that I can get optimum performance from both local Ethernet and radio based connections. · I also run my sendmail, http, ftp and other daemons on the router machine so that it needs to be the only machine to provide others with facilities. · The router machine is a lowly 386DX20 with a 20Mb harddrive. 14.2. IPIP encapsulated gateway configuration. Linux is now very commonly used for tcp/ip encapsulated gateways around the world. The new tunnel driver supports multiple encapsulated routes and makes the older ipip daemon obsolete. A typical configuration would look similar to the following. . . . . . . --- . | Network /---------\ . Network | 154.27.3/24 | | . 44.136.16/24 \ | / | | Linux | . \|/ | | | . | | eth0 | IPIP | . /-----\ /----------\ | ---|---------------| |-----| TNC |----| Radio |---/ | 154.27.3.20 | Gateway | . \-----/ \----------/ | | | sl0 | | | 44.136.16.1 | | | . | | | . | \_________/ . --- . . . . . . The configuration files of interest are: # /etc/rc.net # This file is a simple configuration that provides one KISS AX.25 # radio port, one Ethernet device, and utilises the kernel tunnel driver # to perform the IPIP encapsulation/decapsulation # echo "/etc/rc.net" echo " Configuring:" # echo -n " loopback:" /sbin/ifconfig lo 127.0.0.1 /sbin/route add 127.0.0.1 echo " done." # echo -n " ethernet:" /sbin/ifconfig eth0 154.27.3.20 netmask 255.255.255.0 \ broadcast 154.27.3.255 up /sbin/route add 154.27.3.20 eth0 /sbin/route add -net 154.27.3.0 netmask 255.255.255.0 eth0 echo " done." # echo -n " AX.25: " /usr/local/sbin/axattach -s 4800 /dev/ttyS1 VK2KTJ-0 & sleep 2 /sbin/ifconfig sl0 44.136.16.1 netmask 255.255.255.0 \ broadcast 44.136.16.255 mtu 512 up /sbin/route add 44.136.16.1 sl0 /sbin/route add -net 44.136.16.0 netmask 255.255.255.0 window 1024 sl0 # echo -n " tunnel:" /sbin/ifconfig tunl0 44.136.16.1 mtu 512 up # echo done. # echo -n "Routing ... " source /etc/ipip.routes echo done. # # end. and: # /etc/ipip.routes # This file is generated using the munge script # /sbin/route add 44.134.8.0 netmask 255.255.255.0 tunl0 gw 134.43.26.1 /sbin/route add 44.34.9.0 netmask 255.255.255.0 tunl0 gw 174.84.6.17 /sbin/route add 44.13.28.0 netmask 255.255.255.0 tunl0 gw 212.37.126.3 ... ... ... Some points to note here are: · The new tunnel driver uses the gw field in the routing table in place of the pointopoint parameter to specify the address of the remote IPIP gateway. This is why it now supports multiple routes per interface. · You can configure two network devices with the same address. In this example both the sl0 and the tunl0 devices have been configured with the IP address of the radio port. This is done so that the remote gateway sees the correct address from your gateway in encapsulated datagrams sent to it. · The route commands used to specify the encapsulated routes can be automatically generated by a modified version of the munge script. This is included below. The route commands would then be written to a separate file and read in using the bash source /etc/ipip.routes command (assuming you called the file with the routing commands /etc/ipip.routes) as illustrated. The source file must be in the NOS route command format. · Note the use of the mtu and window arguments on the ifconfig and route commands where appropriate. Setting these parameters to appropriate values improves the performance of your radio link. The new tunnel-munge script: #!/bin/sh # # From: Ron Atkinson # # This script is basically the 'munge' script written by Bdale N3EUA # for the IPIP daemon and is modified by Ron Atkinson N8FOW. It's # purpose is to convert a KA9Q NOS format gateways route file # (usually called 'encap.txt') into a Linux routing table format # for the IP tunnel driver. # # Usage: Gateway file on stdin, Linux route format file on stdout. # eg. tunnel-munge < encap.txt > ampr-routes # # NOTE: Before you use this script be sure to check or change the # following items: # # 1) Change the 'Local routes' and 'Misc user routes' sections # to routes that apply to your own area (remove mine please!) # 2) On the fgrep line be sure to change the IP address to YOUR # gateway Internet address. Failure to do so will cause serious # routing loops. # 3) The default interface name is 'tunl0'. Make sure this is # correct for your system. echo "#" echo "# IP tunnel route table built by $LOGNAME on `date`" echo "# by tunnel-munge script v960307." echo "#" echo "# Local routes" echo "route add -net 44.xxx.xxx.xxx netmask 255.mmm.mmm.mmm dev sl0" echo "#" echo "# Misc user routes" echo "#" echo "# remote routes" fgrep encap | grep "^route" | grep -v " XXX.XXX.XXX.XXX" | \ awk '{ split($3, s, "/") split(s[1], n,".") if (n[1] == "") n[1]="0" if (n[2] == "") n[2]="0" if (n[3] == "") n[3]="0" if (n[4] == "") n[4]="0" if (s[2] == "1") mask="128.0.0.0" else if (s[2] == "2") mask="192.0.0.0" else if (s[2] == "3") mask="224.0.0.0" else if (s[2] == "4") mask="240.0.0.0" else if (s[2] == "5") mask="248.0.0.0" else if (s[2] == "6") mask="252.0.0.0" else if (s[2] == "7") mask="254.0.0.0" else if (s[2] == "8") mask="255.0.0.0" else if (s[2] == "9") mask="255.128.0.0" else if (s[2] == "10") mask="255.192.0.0" else if (s[2] == "11") mask="255.224.0.0" else if (s[2] == "12") mask="255.240.0.0" else if (s[2] == "13") mask="255.248.0.0" else if (s[2] == "14") mask="255.252.0.0" else if (s[2] == "15") mask="255.254.0.0" else if (s[2] == "16") mask="255.255.0.0" else if (s[2] == "17") mask="255.255.128.0" else if (s[2] == "18") mask="255.255.192.0" else if (s[2] == "19") mask="255.255.224.0" else if (s[2] == "20") mask="255.255.240.0" else if (s[2] == "21") mask="255.255.248.0" else if (s[2] == "22") mask="255.255.252.0" else if (s[2] == "23") mask="255.255.254.0" else if (s[2] == "24") mask="255.255.255.0" else if (s[2] == "25") mask="255.255.255.128" else if (s[2] == "26") mask="255.255.255.192" else if (s[2] == "27") mask="255.255.255.224" else if (s[2] == "28") mask="255.255.255.240" else if (s[2] == "29") mask="255.255.255.248" else if (s[2] == "30") mask="255.255.255.252" else if (s[2] == "31") mask="255.255.255.254" else mask="255.255.255.255" if (mask == "255.255.255.255") printf "route add -host %s.%s.%s.%s gw %s dev tunl0\n"\ ,n[1],n[2],n[3],n[4],$5 else printf "route add -net %s.%s.%s.%s gw %s netmask %s dev tunl0\n"\ ,n[1],n[2],n[3],n[4],$5,mask }' echo "#" echo "# default the rest of amprnet via mirrorshades.ucsd.edu" echo "route add -net 44.0.0.0 gw 128.54.16.18 netmask 255.0.0.0 dev tunl0" echo "#" echo "# the end" 15. Discussion relating to Amateur Radio and Linux. There are various places that discussion relating to Amateur Radio and Linux take place. They take place in the comp.os.linux.* newsgroups, they also take place on the HAMS list on vger.rutgers.edu. Other places where they are held include the tcp-group mailing list at ucsd.edu (the home of amateur radio tcp/ip discussions), and you might also try the #linpeople channel on the linuxnet irc network. To join the Linux linux-hams channel on the mail list server, send mail to: Majordomo@vger.rutgers.edu with the line: subscribe linux-hams in the message body. The subject line is ignored. To join the tcp-group send mail to: listserver@ucsd.edu with the line: subscribe tcp-group in the body of the text. Note: Please remember that the tcp-group is primarily for discussion of the use of advanced protocols, of which tcp/ip is one, in Amateur Radio. Linux specific questions should not ordinarily go there. 16. Copyright. The HAM-HOWTO, an introduction to Amateur Radio software available for Linux and information on how to configure some of it. Copyright (c) 1996 Terry Dawson. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the: Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.