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OSPF Network Type on a "point-to-point " ethernet link

We have a two 8540s at the core of our network. Both of these routers are connected to approx. five WAN routers via 100TX CAT5 ethernet cable. These links, being ethernet, default to OSPF network type of BROADCAST (ten total). I was wondering if it would be possible to change the network type to POINT-to-POINT instead. Of course, physically, this is exactly what they are. There will never be other devices are these links as they are just a CAT5 cable with no switches/hubs etc. Do you see any problem with doing so? PROs and CONS? IMHO doing so would simplify my OSPF database. I welcome all opinions.

Thanks,

Jim Coffey

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Re: OSPF Network Type on a "point-to-point " ethernet link

In general if an Ethernet segement is used as a Point To Point connection between two routers (and is only ever going to be a PPP link) I usually configure the link as IP OSPF Network Point-To-Point. This reduces the overhead on the router as it now no longer has to participate or track DR / BDR states. I have sucessfully implemented such designs in large scale Campuses with no bad side effects.

The only negative point to this approach would be if you ever needed to introduce a third router as you would need to take the link down to migrate it back to a Broadcast Multiaccess network.

1 REPLY
Silver

Re: OSPF Network Type on a "point-to-point " ethernet link

In general if an Ethernet segement is used as a Point To Point connection between two routers (and is only ever going to be a PPP link) I usually configure the link as IP OSPF Network Point-To-Point. This reduces the overhead on the router as it now no longer has to participate or track DR / BDR states. I have sucessfully implemented such designs in large scale Campuses with no bad side effects.

The only negative point to this approach would be if you ever needed to introduce a third router as you would need to take the link down to migrate it back to a Broadcast Multiaccess network.

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