Re: redundancy with Adsl modem

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

  yes, I need redundancy. when an line adsl come down all traffic go to
other line adsl. I couldn't have done this on linux machine. if you
has any how to about please post here.

How do you want to do that???

If you have two connections then you have two external IP-s...
If one goes down then you can not simply use the other one...

Just think about these steps:

In normal connection:

1. a local host (A - 192.168.1.1) sends a packet from LAN to an external host (C - 8.8.8.8) 2. the firewall applies source NAT to the packet and sends it out as if it were coming from the firewall's first external IP (B1 - 1.1.1.1)
3. C sends back a reply to B1
4. B1 forwards it with destination NAT to A.
5. go to step 1. or close the connection

If the line goes down between step 2 and step 3 then the reply packet will never get back to B1 and A (because the line is down) !!! If the line goes down after step 4 then you can send it out on the second extrenal IP (B2 - 2.2.2.2) but C will see it as a NEW connection !!!

So I think that your request is impossible on IP level.
However you can use a proxy or a mail server, etc. etc. etc.

Swifty
--
To unsubscribe from this list: send the line "unsubscribe netfilter" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Netfilter Development]     [Linux Kernel Networking Development]     [Netem]     [Berkeley Packet Filter]     [Linux Kernel Development]     [Advanced Routing & Traffice Control]     [Bugtraq]

  Powered by Linux