Routing
Highlighted
Routing

OSPF Neighbor limitation

‎03-10-2009 05:39 AM

We have a (2) node NS-208 cluster running version 5.4.0r10 and we establish an IPSEC VPN tunnel to 250 5GTs. Our routing protocol has been RIPv2 and we are interested in migrating to OSPF but our consultant has informed us that OSPF has a neighbor limitation of 16ish neighbors in an area. So we would have to break up our environment in to multiple areas. I'm unable to find any documentation to support this either in print or online.

 

Any help is greatly appreciated.

3 REPLIES 3
Highlighted
Routing

Re: OSPF Neighbor limitation

‎03-12-2009 01:38 PM

The specifications for the OSPF protocol do not specify any neighbor limitation. Back then OSPF was originally created, routers were not as powerful and breaking up the environment in areas was often necessary to distribute the burden better.

Nowadays you can effortly run OSPF on hundreds of routers in one area. Most likely you are adding unnecessary complexity to the network by dividing it into areas.

To be sure it's advisable to gradually migrate to OSPF and keep an eye on the resource usage of the devices by using a monitoring tool (e.g. Cacti).

Highlighted
Routing

Re: OSPF Neighbor limitation

‎03-13-2009 05:25 AM

Thanks for the reply. Since I posted this question, I spoke to JTAC and they said the NS-208 has a 64 device limitation in an OSPF area. They had me run the following command to determine the max.

 

get sys-cfg | i OSPF

 

Output:

max OSPF instances number: 3
maximum number of redistribution routes into OSPF, BGP number: 4096

max OSPF interfaces number: 64

max OSPF interfaces per one area number: 32

max OSPF routes processed per timer tic number: 20

max OSPF nodes processed in SPF per timer tic number: 10 

 

 

Highlighted
Routing

Re: OSPF Neighbor limitation

‎03-13-2009 12:56 PM

Should you be interested, more information about this can be found in Jeff Doyle blogpost:

 

http://www.networkworld.com/community/node/19293#comment-112350 

Feedback