The Gateways FAQ
Version 1.1
7th February, 1994
0. This is a short FAQ answering some questions about the Internet/AMPRnet
gateways. If you have any suggestions or comments about the content,
please email them to me at one of the following addresses.
Warren Toomey vk1xwt [Make sure you have the most recent copy]
Internet: [email protected]
AMPRnet: [email protected]
BBS: [email protected]
I'd like to thank the following contributors to this FAQ:
Brian Kantor WB6CYT
Tony Querubin AH6BW
Mike Gallaher WA2HEE
and everybody who made suggestions on how to improve it.
The contents of this FAQ are:
1. What's a wormhole? What's a gateway? What's an Internet/AMPRnet
gateway?
2. How do I set a gateway up?
3. Is there a mailing list for gateway discussion?
4. Who else is running a gateway?
5. Is there information about the gateways with only AMPRnet stuff
that I can distribute to the local users?
6. How do I update the gateways/resource file?
7. Do I have to manually extract the routes from the gateways file?
8. Are there maps showing where the gateways are?
9. My gateway locks up. How do I fix this?
10. Is there a domain name server for the .ampr.org domain?
11. How can I get updates into the .ampr.org nameserver?
12. How Does TCP Access and IP Access Work?
Not all of these sections are complete as yet. If you can write/complete
a section, please do so and send it to me!
1. What's a wormhole? What's a gateway? What's an Internet/AMPRnet gateway?
A wormhole is just a two-way "data pipe", say a phone line, that can accept
packets on one end, and spits them out at the other end. There is only one
possible destination. It is like an AX.25 digipeater, and in fact many
wormholes are fashioned to look just like one.
A wormhole doesn't know or care what is in the packets; in particular, it
doesn't do any routing. To use a wormhole, you have to know where its input
port is so you can send your packets through it (as if it were a
digipeater), and what stations are at the other end, so you can address
packets to them.
A gateway, on the other hand, takes incoming packets, and makes a decision
about how to forward on the packet, according to the details in the packet.
It may be able to pass the packet directly to the destination, or it sends
the packets to another gateway for further forwarding. This forwarding is
transparent to users of IP encap gateways - they just specify the
destination IP address and the gateway system takes care of the rest.
Ok, so how does this relate to an Internet/AMPRnet gateway? An
Internet/AMPRnet gateway routes AMPRnet packets between areas that are far
apart, by using the Internet as the medium. Packets are passed by first
wrapping them (also known as `encapsulation') in an IP packet, sending them
to a distant gateway, and unwrapping them there. This allows real-time
long-distance TCP/IP communications. This method of encapsulation can also
be used as a wormhole for AX.25 and NETROM communications.
2. How do I set a gateway up?
First you need a place which has an Internet connection. Next you need to
get permission to put amateur equipment (rig, antenna, PC) in, and then you
need to get permission to connect the PC to the Internet. Getting these
permissions is very dependent on your specific location, who you know and
the rules there etc. If you are unsure about things, other people who have
set up a gateway may be able to help you. See the next section for
information about how to get into contact with them.
If you can get a PC, rig and antenna in, and an Internet connection, you
now need to set up the gateway software. Information about doing this can
be obtained via anonymous ftp from the following machine:
minnie.cs.adfa.oz.au 131.236.20.70
minnie.vk1xwt.ampr.org 44.136.7.129
Anonymous ftp to minnie, cd to gateways, and have a look around.
Information about setting up a gateway can be found in the following files:
newgate.txt - Setting up an Internet/Amprnet gateway, ASCII version
newgate.ps - PostScript version
newgate.zip - Word for Windows version
newgate.tex - LaTeX version
Remember to use binary mode for the newgate.ps and newgate.zip files.
Since this is from "down under", to conserve bandwidth, local copies
(as of April 1995)
can be found here as netgate.txt and
netgate.ps.
3. Is there a mailing list for gateway discussion?
Yes, and if you are intending on setting up a gateway, or you are already
doing so, you should join the mailing list. This way, you will learn of
changes to the other gateways. To join, send some email to Tony Querubin
AH6BW at [email protected], asking to subscribe. When you have
subscribed, you can mail articles to the list by sending them to
[email protected]. Currently, about XXX people are on the
mailing list, and most are willing to help new gateway administrators.
4. Who else is running a gateway?
In order to get your gateway working, you need to install encapsulated
routes to other gateways so your packets will get wrapped and sent to the
correct destination for unwrapping. Information on who else is running a
gateway, what their setup is, email contact addresses, and the routing
lines you should use, can also be found on minnie in the gateways directory
in the file `gateways'. This file is the most up to date information
available about the set of gateways worldwide. It contains a timestamp so
you know how old it is.
5. Is there information about the gateways with only AMPRnet stuff that I
can distribute to the local users?
Yes. The file `resource' on minnie in the gateways directory contains
information about many machines (not just gateways) that can be accessed
through the gateways, and what services the machines provide. The file
contains only AMPRnet information (and no Internet information), and so is
ideal for distributing to your local AMPRnetters. Unfortunately, this file
is not kept as up to date as the `gateways' file, but it is mostly useful.
6. How do I update the gateways/resource file?
This can be done automagically by sending mail with the changes you want to
minnie. The procedure is thus: first you need a program called `diff',
which takes two files, and outputs the differences between the files. If
you have a Unix machine around, you should have this program already. If
not, an MS-DOS version of diff can be obtained via anonymous ftp from
minnie in the gateways directory, file `diff115.zip'. Use binary mode!
Unzip and install the diff program if you don't have it.
Now, get the latest `gateways' file from minnie. Make a copy of it, calling
the copy `gateways.new'. Edit `gateways.new' and make the additions or
changes that you want, and save the edited file. Then do the following:
diff -c gateways gateways.new > out
This will find the differences between the old and new files, and save
these differences to a file called `out'. With this done, you can update
the `gateways' file on minnie by emailing the contents of this file to
[email protected] or [email protected]. Minnie
will receive your email, install the changes, and return some mail to you
indicating that the changes were successfully applied. If you get an error
message back, chances are that you edited an old version of the `gateways'
file.
Similarly, to update the `resource' file, use the method above and send the
changes to resdiff@minnie.
*** Note for new gateway administrators ***
Please use the format used by everybody else in these two files. In
particular, when you insert a gateways entry, include where the route is
for, the Internet and AMPRnet names/addresses of the gateway, an email
contact address, any relevant notes, the date you created/modified the
entry, and the NOS route commands for your routes. Please DON'T use the
words `encap' or `ENCAP' anywhere but in the NOS route lines.
7. Do I have to manually extract the routes from the gateways file?
No, as minnie changes the `gateways' file, she also creates another file
called `encap.txt', which contains only the NOS route commands from the
`gateways' file. You can ftp this file, and source it under NOS to put in
the new routes.
** N.B Remember that your own encap routes are in the file! If you just
source the file, you will destroy your own local routes. To prevent this:
a) Edit out your own encap lines, either manually or
with a program like grep, or
b) Source encap.txt from your autoexec.net, and THEN set up your
local routes; these should override the ones in encap.txt.
If you don't like to manually ftp this file from minnie, you can email
vk1xwt@minnie and be put on a mailing list. As `encap.txt' is created, the
new version will be emailed to you with the subject line `Update:
ENCAP.TXT'.
8. Are there maps showing where the gateways are?
Yes, these can get obtained via anonymous ftp from ucsd.edu, directory
/hamradio/packet/gw in the following formats:
gwmaps-ps.tar.Z PostScript
gwmaps-hppcl.tar.Z HP-PCL format
The maps depict the UUNet mail-only gateways as well as the IP routing
gateways.
9. My gateway locks up. How do I fix this?
Good question. There are several solutions to this, in increasing order of
ruthlessness.
a) Don't run certain servers that lock the system up. The converse
server is a known problem, as is the domain name server.
b) In many cases, the machine is still running NOS, but you just
can't get in. You might try exiting NOS at periodic intervals,
which will free up the used memory, and restart things. This
can be done in software using the `at' command, e.g
at 0001 exit
at 0600 exit
at 1200 exit
at 1800 exit
which will reboot NOS every 6 hours. However, Rogan Clements
notes:
The `at' command does not work if you have the keyboard
locked with the `lock' command. So I put an
at now+(0ne min before reboot) (keyboard password)
and the problem is solved.
Alternatively, you can send a remote reboot packet from another
machine. Check out the NOS documentation (such that it is) for
more information. If you have a Unix machine around and you'd
rather use that, source to a reboot program can be obtained from
minnie in the gateways directory, file `unix-remote.c'.
c) If the machine locks up hard, you might like to try the hardware
developed by Tony Querubin, which monitors the RS-232 port, and
`hits' the reset button if no AX.25 packets are transmitted after
a certain time. Details on this hardware can be obtained from
Tony Querubin. Send him some email at [email protected].
10. Is there a domain name server for the .ampr.org domain?
Yes there is. The Internet machine ucsd.edu is the authorative domain name
server for the .ampr.org domain. Its information is available to all the
other domain name servers on the Internet. Therefore, you do not need to
include it in the list of domain name servers your gateway queries for
information. Just use your local domain name servers.
The gateways also provide an excellent point for non-Internetters to get
ampr.org information. If you can afford it, you should make your gateway a
name server cache, and then AMPRnet people can use you as a domain name
server. To do this under NOS, add the following commands:
domain addserver your.local.dns
domain addserver another.local.dns
domain cache wait 30000
domain cache size 200
domain cache clean off
domain maxwait 30
domain start
11. How can I get updates into the .ampr.org nameserver?
Brian Kantor ([email protected]) runs a mail receiver which takes changes to
the .ampr.org nameserver information, and puts them into the ucsd.edu
authorative server. His instructions on how to use it follow:
To submit entries to the robot, e-mail to [email protected] with the data
in the body of the message. You will receive a confirmation by return mail,
unless your mailer puts bad return addresses in your mail.
Updates are added to the memo database immediately. Each morning at about
4 am UCSD time, the memo database is processed to make a new version of the
ampr.org domain, the net-44 PTR domain, and the amprnet.hosts files that
are available from UCSD's anonymous FTP area. Usually within a day or two
the nameserver process here is restarted and the changes take effect.
Entries consist of three or four key fields and one data field. For example,
wb6cyt in a 44.8.0.1
wb6cyt in mx 10 wb6cyt
wb6cyt in mx 20 cyberpunk.ucsd.edu.
wb6kdt in cname wb6cyt
Observe carefully:
1. '.ampr.org' is assumed and should never appear in any entry.
2. names that appear in the ampr.org domain do NOT end with a dot.
3. names that are external to the ampr.org domain MUST end with a dot.
4. you may NOT have a cname if ANY other data for that name appears.
#
# EOF Gateways FAQ
#
12. How Does TCP Access and IP Access Work?
A file called access.rc on minnie.cs.adfa.oz.au in the hamradio/gateways
directory explains how to do this. It is long so I didn't include it here.
You can source this file from your autoexec.nos batch file, which keeps
things modular.