[c-nsp] C6500 IPv6 redistribute with route-map?

[Mark Tinka]

On Tuesday, December 10, 2013 10:42:34 AM Patrick M. Hausen 
wrote:

> This enables OSPF on the link to my other router *only*.
> OSPF does not by default redistribute connected or
> static routes. The 0.0.0.0 looks insane but keep in mind
> that it’s an inverted (wildcard) mask so essentially it
> says /32.

I have ran OSPF (and sometimes still teach it, although I 
teach and run IS-IS more, nowadays), I just haven't ran it 
on Junos or IOS XR platforms :-).

> I’ve been doing OSPF for quite some years and IMHO this
> is a perfectly valid and sane way to run an ISP with
> subscriber lines. And I know more than one competitor
> (friendly competition ;-) doing exactly the same.
> 
> 
> Now … as far as I found out yesterday …
> 
> IS-IS *does* by default redistribute connected subnets
> even if they are on passive interfaces. Unless you use
> 
> > no isis advertise-prefix
> 
> on the interface level.

I don't do much with IS-IS (keep it really simple), but yes, 
"passive-interface" in IS-IS and OSPF behave differently in 
IOS, as I mentioned before. I'm not sure whether this is the 
spec. or something specific to Cisco, as I've only 
experienced this on IOS.

"passive-interface" in IS-IS basically means:

	- If an interface is defined as passive.
	- Advertise whatever IP address is on it.
	- But don't run IS-IS on it.

> For static subnets it’s the same as with OSPF. I can
> perfectly live with that, now that I know. I’m just
> wondering what the „redistribute connected“ command is
> for in the context of IS-IS, anyway ;-)

In essence, you're right, "redistribute connected" in IS-IS 
is the same as doing "passive-interface" :-).

What I would do, if it were my network, is carry the 
customer's /29 in iBGP, rather than the IGP. This scales 
better, and any volatility on the customer's link is handled 
better by your network since BGP oscillates in much more 
controlled manner than an link state IGP would.

Cheers,

Mark.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 836 bytes
Desc: This is a digitally signed message part.
URL: <https://puck.nether.net/pipermail/cisco-nsp/attachments/20131210/c07e511e/attachment.sig>