Need Help In OSPF Routing

Answered Question
Jan 15th, 2014
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Hello All,

i need help in OSPF routing , my environment is as-

at one location i have two core switches connected with each other using OSPF running area 0. one core switch is connected with MPLS service provider and running OSPF with service provider .

Second core switch is connected with Juniper firewall which is running ospf with core switch using inside interface. i have a site 2 site VPN tunnel with my hub location using same virtual router in firewall which have a default route towards tunnel interface. tunnel interface and indside thereface both have IP address of different network.

when i run sh ip route | i on my core switches i can see one default route from MPLS link which is OK, now i want second default route towards tunnel so that in case of MPLS link fails it can easly switchover. My client don't want to use static route.

Correct Answer by mvsheik123 about 3 years 7 months ago

Hi Sachin,

Check docs to see whether 'default-information-originate' command (on firewall) in OSPF resolves your issue.



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Correct Answer
mvsheik123 Wed, 01/15/2014 - 14:32
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Hi Sachin,

Check docs to see whether 'default-information-originate' command (on firewall) in OSPF resolves your issue.



Jon Marshall Wed, 01/15/2014 - 15:27
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Just to add to MS post. If you do originate a default route from the firewall you need to be careful because depending on the cost of the current default route the new one might be better or equal cost in which case you could end sending some or all of the traffic via the backup link.

From your description one core switch receives a default route from the MPLS provider, is this from a router or is it a direct connection into your switch ? It also sounds like the other core switch then also gets this default route so how are the core switches connected.

You do need to be careful that the right default route is chosen ie. the one via the MPLS network.

Just to point out the obvious, using a floating static on the core switches would work fine because the only time they would be used is if the MPLS provider stopped sending the default route ie. the MPLS link was down but you say the client does not want this.



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