IP failover

sanjibgupta · 05-03-2007, 01:36 AM

Hi
Can i have 2 (live) ip enteries od the same server in the same name to the name server?
How should it be done so that if one is down th other second ip becomes active
Sanjib gupta

acid_kewpie · 05-03-2007, 03:18 AM

sorry, that makes little sense, you seem to jump from DNS cname's to hardware failover in a single sentence... you can use as many cnames in a dns record as you wish, and point many domain names to a single ip address. this has nothign to do with resilience though.

sanjibgupta · 05-03-2007, 04:03 AM

then what should i do so that if my eth0 is down the other eth1 gets the same name

acid_kewpie · 05-03-2007, 07:30 AM

eth0 doesn't have a "name" other than "eth0", it has an ip address. if this is actually a question about network resilience, and nothign to do with cnames at all, you need to explain a lot more about your local topology.

sanjibgupta · 05-04-2007, 12:39 AM

Thanks for your reply

i have 2 cards to my webserver eth0->202.141.xxx.26 eth1->203.197.xxx.10 both are live ip connected to internet by two service provider.

www.xxx.com is the nameserver entry to 202.141.xxx.26
but my leased line goes down quite often and hence my webserver is down

What can be done so that the same nameserver entry (www.xxx.com) be associated with 203.197.xxx.10

so that the webserver can be connected on both ip with same name.

Both webserver and the nameserver runs on Redhat Enterprise 3.0

Sanjib gupta

acid_kewpie · 05-04-2007, 01:50 AM

well firstly are you confident that requests to the secondary ip will work? unless you're routing table and iptables whatnots are correctly configured then all traffic will still try to leave the box the original way, down the dead line.

as for failover itself, you would want to use DNS i guess, but the changes made on your dns providers servers can take up to 2 days to propagate round the internet, nothing can be instant due to the nature of DNS and record caching.

sanjibgupta · 05-04-2007, 04:01 AM

Thanks for your help.
yes i had done proper routing and the packets are being send through the eth1 when eth0 down.
Sanjib gupta