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New Member

Routing suggestions - Multi-site/multi-link

Looking for suggestions on routing for a school system...

The main site currently has one T1 to the Internet and will be getting a second, probably from a different provider (for redundancy and extra bandwidth, both). Behind the 2800 series router is a PIX with three interfaces (inside, outside, DMZ).

The second site has its own T1 to the Internet with a 1600 series router behind which is another PIX (inside and outside). Connected to the internal network of both sites is another T1 for communications between the two sites (IP telephony and data).

Design goals, in order of importance:

1. Use the two Internet T1s at site #1 to maximize available bandwidth and redundancy. We will have to deal with the asymmetric routing as the two links will likely use different ISPs.

2. If either site #1 or site #2 loose their direct Internet connectivity, try to use (at most half of) the link between campuses for limited Internet connectivity.

3. If the T1 between the two sites goes down, bring up a VPN across the Internet to restore connectivity.


Re: Routing suggestions - Multi-site/multi-link

Hi Apu,

You can design the N/W in 2 ways:

1. Run the EBGP multihoming between the 2 ISP's and use one ISP for upstream traffic and another ISp for downstram traffic and in case either of the ISP fails that traffic should use the T! between the sites to router the traffic. You might have to use PBR along with BGP to carry it out.

2. If you are not running BGP then you have to simply design your PBR to carry outt the traffic accross the 2 sites.


-amit singh

New Member

Re: Routing suggestions - Multi-site/multi-link

I should have added... The tenative plan is to use something pretty close to "Scenario 1" at -- just looking for any real-world feedback.

Suggestions, insights, pitfalls we can avoid, ... stuff like that.