AW: ISIS --- advertise passive-only

From: Danny Muizebelt (Danny.Muizebelt@osiatis.at)
Date: Thu Oct 20 2005 - 09:28:21 GMT-3


Hi Robert,

If I don't put the "ip router isis" no neighbour relationship is possible over this interface. But while configuring this neighbour relationship I also add the connected network/interface to the link-state database. For a BGP network I only need loopback addresses and all other internal networks would only clutter up my ISIS table.

For instance, which interfaces are on passive? Loopback and customer interfaces. Which networks are interesting for BGP? Loopback and customer networks.

So I think that the "advertise passive-only" option is pretty nifty to separate the tasks each routing protocol is supposed to do. Too bad they didn't think sooner of it.

I don't think it's possible to set up a some sort of clns unicast neighbour statement without using the "ip router isis" command.

-Danny

> -----Urspr|ngliche Nachricht-----
> Von: McCallum, Robert [mailto:robert.mccallum@thus.net]
> Gesendet: Donnerstag, 20. Oktober 2005 14:15
> An: Danny Muizebelt; Cisco certification
> Betreff: RE: ISIS --- advertise passive-only
>
> I must be missing something here but to advertise a connected
> network in
> isis you must place the ip router isis command on the interface. If
> you
> don't want to advertise a certain interface then just don't place
> that
> command on the interface.
>
> Robert McCallum CCIE #8757
>
>
>
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
> > Behalf Of Danny Muizebelt
> > Sent: 20 October 2005 12:13
> > To: Cisco certification
> > Subject: ISIS --- advertise passive-only
> >
> > Hi Group,
> >
> > I was looking for a feature in ISIS where I could suppress
> > the networks of connected interfaces toward neighbour ISIS
> > routers. I only wanted the loopback addresses advertised by
> > the IGP so BGP would take care of the rest.
> >
> > It started off very well on my 1841 with 12.4(1a) loaded (There is
> no
> > 12.2T) and what did I find?
> >
> > advertise Control which IP routes flow in L1 and L2 LSPs
> > R8(config-router)#advertise ?
> > passive-only only interface address of passive interfaces
> > R8(config-router)#advertise passive-only ?
> > <cr>
> > R8(config-router)#advertise passive-only
> >
> > And this works like a charm:
> >
> > R8.00-00 0x000000F1 0x71DB 993
> > 0/0/0
> > Auth: Length: 7
> > Area Address: 10
> > NLPID: 0xCC
> > Hostname: R8
> > IP Address: 10.100.100.8
> > Metric: 0 IP 10.100.100.8 255.255.255.255
> > Metric: 10 IS R8.02
> > Metric: 10 IS R8.01
> > R8.01-00 0x000000E9 0xCFD7 1142
> > 0/0/0
> > Auth: Length: 7
> > Metric: 0 IS R8.00
> > Metric: 0 IS R9.00
> >
> > So I was slightly depressed when I discovered that the 12.2T
> > release didn't have this feature or any other possibility to
> > suppress advertised networks.
> >
> > It seems to me that "advertise passive-only" was really
> > implemented for ISIS/BGP or ISIS/MBGP combos for larger ISP
> > backbone networks.
> >
> > Or is there another way of only advertising your loopbacks over
> ISIS?
> >
> > Cheers,
> >
> > Danny
> >
> >
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Diese Information ist vertraulich und ausschlie_lich zur Kenntnisnahme durch den (die) genannten Adressaten bestimmt.
Wenn Sie nicht der vorgesehene Adressat sind, informieren sie uns bitte unverz|glich.
The information herein is confidential and intended solely for the attention and use of the named addressee(s).
If you are not the intended recipient please inform us immediately.

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