ISP redundancy and with IPFW
agentflicker at hotmail.com
Mon May 24 06:31:52 PDT 2004
IPFW newbie question.
I am lucky enough to have 2 ADSL connections with 6 static addresses on each
router. I have a web server that needs to be always availaible from the
internet for our road warriors. What I would like to do is give this web
server a private address say 10.0.0.1 and put it behind a freeBSD/IPFW
firewall. I would then like to nat this private address to a public address
from each ISP's range.
Say 188.8.131.52 for ISP1 (The ISP router address is 184.108.40.206)
and 220.127.116.11 for ISP2 (The ISP router address is 18.104.22.168)
This would mean that our roadwarriors could type into their browsers either
http://22.214.171.124 or http://126.96.36.199 and arrive at the web server.
The problem I'm not sure about is how to configure the return routing of the
packets (I don't think I can use a default router on the firewall).
Say for example ISP1 was down - 188.8.131.52 does not work, so the user types
184.108.40.206 the packet arrives at the firewall is natted to 10.0.0.1 and sent
to the web server. The retun packet is returned to the firewall where the
souce is "unnattted" to 220.127.116.11 (destination could be anything), how do I
specify a rule that says for this source address (in ISP2's network) send
the packet to ISP2's router (18.104.22.168)?
Obviously I cannot route by destination address as this could be anything
(for the return packets).
Is this possible with IPFW? and Nat together?
Has anyone a similar rule set that they could send me?
Cheers, Simon Chang.
MSN 8 with e-mail virus protection service: 2 months FREE*
More information about the freebsd-ipfw