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OSPF Question

dppagc

What is the difference between

A)

int fa0/0
ip add x.x.x.x y.y.y.y
no shut

router ospf 1
net x.x.x.x <y wildcard mask> area 0

VS

int fa0/0
ip add x.x.x.x y.y.y.y
ip ospf 1 area 0
no shut

Both of them achieve the same purpose so why the difference?

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Comments

atorven

No difference at all, except for admin purposes i.e. if you had to enable ospf on a router with loads of interfaces, option A would be the quickest.

EdTheLad

dppagc wrote: »

What is the difference between

Both of them achieve the same purpose so why the difference?

B is the newer Cisco preferred method, it wasn't always available where as A is from day one ospf config. XR only supports B which is the direction cisco is moving towards.

xnx

I use method B as it's easier to follow when reading through configurations

DKempeneers

I think that B is only way to declare a net/int into OSPFv3
EdTheLad can you confirm ?

mackenzae

Option B would also help prune which interfaces send out Hello messages compared to option A especially if your network command encompasses a large network range like a class A

Fitzi

DKempeneers wrote: »

I think that B is only way to declare a net/int into OSPFv3
EdTheLad can you confirm ?

Yes, for IPv6 both ospfv3 and eigrp require configuration per/on the interface.

eten

same results in this example, but when configured under the interface where a secondary IP address exist, it will be included in the ospf process.

phantasm

atorven wrote: »

No difference at all, except for admin purposes i.e. if you had to enable ospf on a router with loads of interfaces, option A would be the quickest.

Learn to script. Option B is the new standard and as stated, OSPFv3 and EIGRP for IPv6 only support per interface configuration. In the end it's much neater anyway. I prefer the way it looks.