bgpd.pl, a BGP daemon written in perl

Steven Hessing steven at xs4all.nl
Mon Apr 23 12:12:50 UTC 2001


A first release of bgpd.pl, a limited functionality BGP daemon written in 
perl is now available. This software is alpha stage. Further testing is 
required for:
- interoperability testing with other BGP software (currently Zebra and 
Cisco have been tested)
- testing with multiple concurrent BGP connections plus local-RIB route 
selection

This software is not intended to be used for packet forwarding purposes, 
indeed functionality is missing to fullfil this role. This tool can be 
useful for real-time monitoring of BGP routing tables. The software can 
easily be extended to implement specific monitoring functions since it has 
been written in perl and its datatypes are well documented. Which 
monitoring functions could be useful I leave up to your imagination.

I have attached the README of the package to the end of this mail. The 
software can be downloaded from:
   http://www.fasttracknetworks.com/software/bgpd.pl/

Bug reports are appreciated and if someone is willing to set up a eBGP 
connection to me then I could test the route selection code.

- Steven Hessing

README:
bgpd.pl
Version 0.01
(C)2001 Steven Hessing
steven at xs4all.nl

bgpd.pl is a partial implementation of the BGP protocol (RFC1771) in perl.
It was written as a tool to monitor BGP routing updates. It is NOT written
to be used as a BGP router in an operational network, in fact is has no
support to propogate routing information because there is no code to send
BGP UPDATE messages. bgpd.pl also does not touch the routing table of the
host it runs on.

With the constraints described in the above text, the software supports the
following RFCs to the extend indicated:
RFC1771 - Border Gateway Protocol version 4
   adj-RIB-out not maintained, no outgoing BGP UPDATE messages, BGP TCP 
sessions
   are not initiated. No Finite State Machine support.
RFC1863 - BGP Route Server
   Route Server client behaviour is supported. bgpd.pl can't act as a route
   server
RFC1997 - BGP Communities attribute
   supported
RFC2385 - Protection of BGP Sessions via the TCP MD5 Signature Option
   not supported
RFC2439 - BGP Route Flap Damping
   not supported, not needed because we don't send out UPDATES
RFC2545 - Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing
   not supported
RFC2547 - BGP/MPLS VPNs
   not supported
RFC2796 - BGP Route reflection
   supported
RFC2842 - Capabilities Advertisement with BGP-4
   We don't follow this RFC when a neighbour doesn't support a capability that
   we do. We keep announcing the same set of capabilities.
RFC2858 - Multiprotocol Extensions for BGP-4
   almost no support. We recognise the RFC2842-capability announcement
RFC2918 - Route refresh capability for BGP-4
   supported
RFC3065 - Autonomous System Confederations for BGP
   supported

The following RFC drafts are not yet supported:
draft-ietf-id-bgp4-12
draft-ietf-id-route-filter-03
draft-ietf-id-restart-00
draft-ietf-id-as4bytes-01
draft-ietf-id-route-oscillation-00

Multiprotocol support:
Although the MP capability is accepted and announced in the BGP OPEN message,
all MP path attributes in BGP UPDATE messages are silently ignored. There is
no support for the MPLS/BGP VPN application or IPv6. This is planned for
future releases.

DOWNLOAD:
The home page of bgpd.pl is:
         http://www.fasttracknetworks.com/software/bgpd.pl/index.html

INSTALLATION:
- download and install Net::Patricia from
          http://net.doit.wisc.edu/~plonka/Net-Patricia/
- cd <parent-dir>; tar zxvf bgpd.pl.tar.gz

USAGE:
- cd into the bgpd.pl directory
- ./bgpd.pl [--log [syslog|file|stdout] ] [ --daemon] [--debug [level] ]
                 [ --as <asnumber> ]
- There are many debugging levels, read the `LOGGING' file. If you enable full
   logging then prepare for a lot of logging information! For a full BGP table
   you'll get log file of close to 100MB
- The default AS is 65100 which is a private AS.
- set up a BGP session from your router to the host on which you run bgpd.pl
   If you use a private AS then don't forget to enable eBGP multihop on your
   router. If you prefer to use iBGP then I would suggest configuring your
   router as a route reflector for this BGP connection.
- edit the bgpd.pl script to get the kind of monitoring functionality that
   you need. You'll mostly use the %adjRIBin, %localRIB and %peers hashes. They
   are described in the file DATATYPES
- if you have specified `file' or `stdout' for logging then you can send
   the bgpd.pl process a kill -1 to get a dump of the routing table.


SECURITY CONSIDERATIONS:
- connecting this alpha-stage software which has undergone limited testing
   to your production network can result in considerable damage to your
   network! Use this software at your own risk!
- this software runs as root because it needs to connect to the TCP/BGP port.
   The code does not switch back to a regular UID yet. It opens a logfile
   for writing in the current working directory under the name bgpd.log. Make
   sure that this is not a (sym-) link!

INTEROPERABILITY:
- bgpd.pl has succesfully maintained BGP sessions with:
   - Zebra 0.91A
   - Cisco IOS ios 12.0(14)S2 running on a Cisco 7206

WARNING:
There should be no problem running a bgp connection between a router in a
production network and bgpd.pl because in no circumstance will bgpd.pl
propogate routing information nor will it change the routing table of the
host it runs on. BUT, this is alpha code and has undergone limited testing
so use it at your own risk. Better connect it to your test network for now.





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