cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
513
Views
4
Helpful
5
Replies

OSPF and underlying layer 2 mutually exclusive ?

zillah2004
Level 1
Level 1

The OSPF network type and the underlying layer 2 interface type are mutually exclusive.

What does that mean ?

1 Accepted Solution

Accepted Solutions

Hello,

I guess what is meant by that is that when you configure an OSPF network type, that type will take precedence over whatever the underlying network type is. An example would be a physical frame relay interface, which defaults to non-broadcast multi-access. If on that interface you define an 'ip ospf network point-to-point', the link will effectively become a point-to-point link...

Does that make sense ?

Regards,

GP

View solution in original post

5 Replies 5

Hello,

I guess what is meant by that is that when you configure an OSPF network type, that type will take precedence over whatever the underlying network type is. An example would be a physical frame relay interface, which defaults to non-broadcast multi-access. If on that interface you define an 'ip ospf network point-to-point', the link will effectively become a point-to-point link...

Does that make sense ?

Regards,

GP

It means that if you set the OSPF network type on the interface explicitely, OSPF will treat the interface the way you've configured it, rather than that the layer 2 link information indicates the link type actually is. In other words, if you have a broadcast link, like an ethernet, and you configure it as a point-to-point, then OSPF treats it as a point-to-point, sending unicast hellos, etc, rather than a broadcast link.

HTH.

:-)

Russ.W

"If on that interface you define an 'ip ospf network point-to-point', the link will effectively become a point-to-point"

That means the administrator will override the default configuration, by doing this

Thanks Russ

Thanks GP

Review Cisco Networking for a $25 gift card