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New Member

Three T1 lines 2 different providers nad a 2600 router.

I need to setup three T1 lines from two differnet ISP into a 2600 router. 2 are from our primary provider and the third is from the backup provider. The backup can not provide BGP so is there anyway I can put all three into the 2600 router (3 wic cards already installed) and set it up to automatically default over to the back up line in case the primary goes down? Something like OSPF?

The internal network is private IP addressing while we NAT out through 1 public IP. Any help would be great. Thanx.

3 REPLIES
New Member

Re: Three T1 lines 2 different providers nad a 2600 router.

Hi

What is your 2600 model??

Bronze

Re: Three T1 lines 2 different providers nad a 2600 router.

You could point a floating static default route out the 2nd provider's T1 interface. If you run BGP with the first provider, the floating route will kick in if the BGP announcements from that provider go away (i.e., when the link goes down). But presumably you'll have to configure NAT so that traffic going to the 2nd ISP is NAT'd to a different address.

Silver

Re: Three T1 lines 2 different providers nad a 2600 router.

A couple of notes on Terry's suggestion:

1 - you only _need_ to run BGP with ISP 1 if you can't reliably detect link down state. If your existing 2xT1 config to your preferred ISP is correctly set up, no changes are required.

2 - Without BGP, you can't multihome so you won't have a stable IP address from the viewpoint of the outside world. This is OK for inside users browsing the Internet and for email, but not OK if your are running a web server or other outside accessed service (other than email).

3 - Once you have the NATs configured and failover working, don't forget to test the backup ISP connection from time to time. Remember that links do not get fixed until you report them down, so if you don't test routinely, the probability of the link working when you need it approaches zero as time goes on.

Good luck and have fun!

Vincent C Jones

www.networkingunlimited.com

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