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New Member

OSPF and NAT

We bought out another company and are connecting our networks. Unfortunately their numbering clashes with one of our own.

I am planning on setting up NAT on their router to NAT their addressing to something else but have a question regarding OSPF. I need OSPF to propagate the NATTED subnet and not their true subnet.

Is this possible?

Denny

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Gold

Re: OSPF and NAT

Absolutely possible. From the router that does NAT, the subnet can be originated as external - "redistribute static subnets".

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6 REPLIES
New Member

Re: OSPF and NAT

Bump..

Is this possible?

If not, any recommendations? We use OSPF to maintain floating static routes for DDR backups.

Renumbering one of the subnets is not an option at the moment.

Denny

Hall of Fame Super Gold

Re: OSPF and NAT

Absolutely possible. From the router that does NAT, the subnet can be originated as external - "redistribute static subnets".

Remember to rate useful posts!

New Member

Re: OSPF and NAT

That is exactly what I was looking for.

Thank you,

Denny

New Member

Re: OSPF and NAT

Okay, I guess I need more help.

How do I redistribute a static subnet or inject a subnet into OSPF to be propagated?

I've used the redistribute static command before, but I actually had a route in my routing table.

On the NAT router, this subnet solely exists in a NAT translation.

Thanks,

Denny

Re: OSPF and NAT

You can configure a static route to point to the null0 interface like this one;

ip route <172.16.1.0 255.255.255.0> null0

This would cause the route to be put into the routing table as a static route. Substitute the IP with your NAT IP.

HTH

Sundar

New Member

Re: OSPF and NAT

Thank you so much. That worked like a charm.

Denny

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