ENCAP.TXT

Name

ENCAP.TXT -- Amprnet Encapsulated Routing File (optional).

Description

This is *not* an XRPi configuration file, but XRPi is capable of reading it.

ENCAP.TXT is a text file which contains a huge list of amateur IP routes and the Internet addresses of IPEncap gateways which handle them.

If this file is present when XRPi boots up, it will read the routes into its IP routing table.

If you are not running an amprnet "gateway", or have set up your own encap routes in IPROUTE.SYS, or you are using RIP2 to obtain your routes, you do not need this file.

Format

The format of routing entries in ENCAP.TXT is as follows:

	route addprivate 44.131.91.0/24 encap 62.31.206.176

The "addprivate" stipulates that the route should be hidden from users, i.e. not displayed by the IPROUTES command.

The "44.x.x.x/xx" part specifies which amprnet route(s) this entry applies to.

The "encap" part tells XRPi to use IPEncap protocol, i.e. it is the same as using routing mode "e".

The final field is the Internet IP address of the gateway which handles the specified amprnet route(s).

Files

If required. ENCAP.TXT should be located in same directory as XRPi.

Notes

ENCAP.TXT is subject to frequent modification, so you will need to obtain updated copies from time to time, and use IP ROUTE LOAD (or restart XRPi) to load them.

A script file to obtain and edit the ENCAP.TXT can be run by the Linux task scheduler, and IP ROUTE LOAD can then be called afterwards by a suitable entry in CRONTAB.SYS.

Caveats

If you are a gateway, you must remove your own entry from ENCAP.TXT before loading it, otherwise catastrophic looping will occur.

ENCAP.TXT contains over 500 entries, and may make your IP routing slower, because all those routes must be searched recursively for every single datagram routed by your system. With a fast computer or low data rate you probably wouldn't notice the difference however.

Background

IPEncap (usually called "encap", but sometimes erroneously called IPIP) "encapsulates" amateur IP within the payload of public (Internet) IP datagrams. Thus it is sometimes called IP-over-IP or IP-within-IP, but should not be called "IPIP", because that is an older version of the protocol. Encap is assigned IP protocol number 4, and IPIP is protocol 94.

Encapsulation allows amateur IP (44.x.x.x addresses) to be "tunnelled" or "wormholed" across the internet, between amprnet gateways. In order to do this, each gateway needs to know the Internet addresses of the other gateways, and which amprnet datagrams shoule be sent to which gateway. That information is located in ENCAP.TXT.

In order to keep the amprnet secure, the gateway owners need to prevent their IP addresses from becoming public knowledge. Thus the contents of ENCAP.TXT are a closely guarded secret. The file is obtained from an FTP server whose address is known only to the gateway sysops.

See also

IPENCAP(5) -- IP-within-IP Encapsulation.
IPROUTE.SYS(8) -- IP Routing and Configuration File