From: michael schwarz (flying_eskimo@hotmail.com)
Date: Fri Oct 25 2002 - 15:58:21 GMT-3
You can use passive int for eigrp/ospf but it does not operate the same as
RIP and IGRP.
With RIP and IGRP you are correct in saying that the configured interface
"listens" wisely for updates but does not talk, or send updates.
However EIGRP does not operate that way.
In EIGRP and OSPF configuring an interface as passive effectively shuts down
the sending and recieving of hello packets. Obviously this causes any
neighbors hanging off that interface to be unable to form an adjacency with
this router, therefore you got nothing. Basically if you want to "turn off"
the protocol on a specific interface then use passive-int on OSPF and EIGRP.
In ospf though best practice would be to specifically enable ospf per int
using the net/area command. I believe that OSPF also views that
passive-interface as a stub network in the linkstate db.
BGP does not have a passive command that i know of. Someone please correct
me if im wrong. You probably want to use neighbor shutdown or one of 20
million possible ways of filtering bgp routes depending on what you are
doing.
If you want EIGRP or OSPF to act like RIP/IGRP (listen wisely but not talk)
you need to use a distribute list out. The hellos are not suppressed so
adjacencies form, routes are recieved from neighbors, but not SENT. and
this horse is now dead.
michael
----- Original Message -----
From: "Jay" <ccienxtyear@hotmail.com>
To: "Tom Young" <gitsyoung@yahoo.co.jp>; <ccielab@groupstudy.com>
Sent: Thursday, October 24, 2002 9:53 AM
Subject: Re: passive-interface command
> what I think makes the different is that OSPF has areas. So on a router,
if
> you have 2 ethernet interfaces and you are running OSPF and have defined
an
> area for the subnet thats on one of the ethernet interface, OSPF will not
> send hellos to the other ethernet interface since it is not part of an
OSPF
> area. Unlike Rip, IGRP & EIGRP, theres no areas. When you configure these
> protocols on a router, it will send hellos, broadcast to all interfaces on
> this particular router, unless you passive them.
>
> -Jay
>
>
>
>
>
> ----- Original Message -----
> From: "Tom Young" <gitsyoung@yahoo.co.jp>
> To: <ccielab@groupstudy.com>
> Sent: Wednesday, October 23, 2002 10:42 PM
> Subject: passive-interface command
>
>
> > Hi, group
> >
> > Sorry for a simple question about the passive-interface
> > command, I know in the sence of distributing different
> > routing protocol we oftenly use the passive-interface
> > command, and I notice it is always rip , igrp, and eigrp
> > use it, (surpess rip eigrp's message to other area) for
> > the ospf and bgp it is always not use it, I don't know
> > why...
> > If you said rip and eigrp has the broadcast or
> > multicast address, but the ospf also has multicast address
> > right?
> >
> > Thanks alot
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Yahoo! BB is Broadband by Yahoo! http://bb.yahoo.co.jp/
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