multiple gateways

[blobaugh]

Is there a way to give RedHat more than one gateway? So if one of the gateways goes offline it will switch to the other one? I have RedHat 9 and there is a setup util for networking, but it only lets me add one gateway.

[GaryJones32]

there are two (possibly more) daemons that run on linux for dynamic routing
gated
and
zebra

i think zebra is the best
http://www-106.ibm.com/developerworks/linux/library/l-emu/

they both can use the two common protocols
SOPF and BGP4

beyond that it's a mystery to me

[blobaugh]

Ok, I took a quick look at that and it looks like it does the routing. I just want to be able to put in multiple gateway addrs that way when one goes down it will switch to the other. In windoze you can just add them in tcp/ip settings

[GaryJones32]

BGP4 is (Border Gateway Protocol) (rfc 1771)
it's routing yes but it's dynamic routing of your gateway traffic
which is what you are talking about

the kernel level routing you are mentioning is not something linux will do otb
but
i have seen where these guys have done it by patching the kernel for multiple gateway paths

http://www.ssi.bg/~ja/

there are some instructions there as well

http://www.ssi.bg/~ja/nano.txt

does not look for the faint of heart but might be fun
(if it ain't broke you ain't finished tweeking !)

[techwise]

I am being a little naive but why couldnt you just write a perl or shell script to regularly ping the gateway, then if no response is given for a period of time the script shanges the systems GW.

The only issue I see is, presumably, the other GW would be on a seperate network. In which case it seems like you would need more that one NIC and a bit more sophisticated script to get the the bridge across to the GW of the other net.

Mike

[GaryJones32]

Originally posted by techwise
I am being a little naive but why couldnt you just write a perl or shell script to regularly ping the gateway, then if no response is given for a period of time the script shanges the systems GW.

The only issue I see is, presumably, the other GW would be on a seperate network. In which case it seems like you would need more that one NIC and a bit more sophisticated script to get the the bridge across to the GW of the other net.

Mike

Please forgive if it seems I'm stealing your thread ..........
a script that simply sends info out whatever gateway that responds at the moment by altering route tables will of course function on some level BUT i think and this is only a guess that communications initiated through the other gateway will get lost yes??
i'm not really sure.
this is why there is border gateway protocol i think......

On the other hand seems like if you didn't want to share the traffic between the two but only wanted one to take over if the other went down.
somehow just start one and it will automatically be default .. then if it goes down the second could be started and it would automatically be default then if it goes down restart the first one and so on...
i bet a script could do that...