[c-nsp] ospf (passive-interface default)

[Mark Tinka]

On 3/Mar/15 23:27, Aaron wrote:
> BTW, incase you didn't know... Look how cool IOS XR is.... it actually does
> it per interface AND nicely organized under the ospf construct
>
> ...kind of cool that you don't have to specify subnets and secondary
> subnets... just advertises any and all subnets that are on the following
> interfaces...

As I mentioned in a previous post, it's been possible to run OSPFv2 at
the interface level for years now. It'd be my recommendation.

In IOS, however, "passive-interface" works differently from IS-IS. From
my experience (well, 12.0S on the XR 12000 anyway), "passive-interface"
for a Loopback interface doesn't work unless you either run OSPF on the
Loopback interface or add the Loopback's IP address as a "network"
statement. I find this really odd, and our Cisco SE says that's how it's
supposed to work.

IS-IS on IOS, on the other hand, works as expected - "passive-interface"
introduces whatever subnet is on an interface into the IS-IS LSDB, but
does not run IS-IS on that interface. Interestingly, OSPF works like
this on Junos (which seems natural). So not sure whether this issue is
specific to IOS.

At any rate, I'm an IS-IS house so don't really have much interest in
digging deeper into this.

Mark.