multiple routes

Ammad · 08-01-2007, 10:58 PM

i have to Internet connections, i want set it like if one (ISP) goes down, all traffic redirect to another link (ISP).
for this, i have an idea to ping yahoo and google after 5 minutes interval, if both response "request time out" then my script will delete default gateway of ISP-1 and add default gateway to ISP-2.

i am confuse how do i set answer from ping of yahoo/google is down .

or
Any one knows best than this to set failover link.

blackhole54 · 08-02-2007, 12:49 AM

Quote:

Originally Posted by Ammad

i am confuse how do i set answer from ping of yahoo/google is down .

If none of the ping attempts work, ping will return a non-zero exit code. So you could:

Code:

if ! ping -c 1 yahoo.com &> /dev/null  && ! ping -c 1 google.com &> /dev/null; then

#   add your routing changes here

fi

Make sure you limit the number of ping attempts with the -c option, or the ping command will never terminate.

Quote:

or
Any one knows best than this to set failover link.

I think there is a better way to do this, but it is beyond my knowledge.

vjn · 08-02-2007, 01:17 AM

Hi,

you can add both ISP ip in your linux box as a gateway.So if one will down the packet will go second ISP ip addr.

Vijayan
Team Safesquid

rossonieri#1 · 08-03-2007, 07:52 PM

Quote:

Originally Posted by Ammad

i have to Internet connections, i want set it like if one (ISP) goes down, all traffic redirect to another link (ISP).
for this, i have an idea to ping yahoo and google after 5 minutes interval, if both response "request time out" then my script will delete default gateway of ISP-1 and add default gateway to ISP-2.

hi,

i think you are doing it too much,
just do like vjn said - but with 1 of the gateway metric set higher.

like 0/0 dev eth1 metric 1 and the other 0/0 dev eth2 metric 10.

this will activate both gateway but - 1 will be passive until something trigger it to active.

HTH.