From: Craig King (cking007@xxxxxxxxxxx)
Date: Thu Dec 06 2001 - 17:09:16 GMT-3
AFAIK, your statement is correct (I'm far from an expert on ISIS). The ATT
(attached) bit is only set to 1 when it has formed an adjacency with another
L2 router (and hence has connectivity to the backbone). Only then can a
default route be advertised to the L1 routers in the area.
HTH,
Craig
>From: Jim Brown <Jim.Brown@CaseLogic.com>
>Reply-To: Jim Brown <Jim.Brown@CaseLogic.com>
>To: "'Craig King'" <cking007@hotmail.com>, ccie2001ca@yahoo.ca
>CC: ccielab@groupstudy.com
>Subject: RE: ISIS L1 router's default route
>Date: Thu, 6 Dec 2001 10:44:02 -0700
>
>This explains something I have been struggling with. I knew about the
>default advertisement and clns on the interface, but I was unaware of the
>need for an L2 adjacency for the advertisement of the default route.
>
>Please clarify/validate my statement....... An L1/L2 router will not set
>the
>ATT bit unless it has formed and adjacency with another L2 router?
>
>-----Original Message-----
>From: Craig King [mailto:cking007@hotmail.com]
>Sent: Thursday, December 06, 2001 8:52 AM
>To: ccie2001ca@yahoo.ca
>Cc: ccielab@groupstudy.com
>Subject: Re: ISIS L1 router's default route
>
>
>A default route is automatically generated by the L1/L2 router when it has
>established an adjacency with another L2 router. Once the L2 adjacency is
>created, the L1/L2 router knows that the backbone area is reachable and can
>default L1 traffic into it. No need to use "default-information
>originate".
>
> I'm only using "ip router isis" on the interfaces, so I doubt that "clns
>router isis" is needed either.
>
>HTH,
>Craig
>
> >From: "Clarke J" <clark.j@163.com>
> >Reply-To: "Clarke J" <clark.j@163.com>
> >To: "CCIE Candidate" <ccie2001ca@yahoo.ca>
> >CC: "CCIE-Groupstudy" <ccielab@groupstudy.com>
> >Subject: Re: ISIS L1 router's default route
> >Date: Thu, 6 Dec 2001 09:54:57 +0800
> >
> >I think you'd better configure " clns router isis " under interface .
> >
> >----- Original Message -----
> >From: "CCIE Candidate" <ccie2001ca@yahoo.ca>
> >To: <ccielab@groupstudy.com>
> >Sent: Thursday, December 06, 2001 08:55
> >Subject: ISIS L1 router's default route
> >
> >
> > > Hello group:
> > >
> > > I 've read in the documents that L1/L2 router acts as
> > > a default gateway for all L1 routers, but i could not
> > > make it work. Infact, there is no default route in the routing
> > > table. One way I can think of is to use
> > > "default-information-originate" but what needs to be done to use
> > > the ATT bit advertised by L1/L2 routers ?
> > >
> > > Thanks in advance
> > >
> > > KJ
> > >
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:32:39 GMT-3