From: Chris Hugo (chrishugo@xxxxxxxxx)
Date: Mon Aug 05 2002 - 17:41:32 GMT-3
Just adding to Eric's post. With distance-vector protocols (rip,igrp) the state
ment that Eric wrote is correct. With Eigrp and OSPF the passive interface actu
ally blocks hello packets from being sent. Hello packets help a routing protoco
l KNOW if their neighbor is dead or alive. When you enable passive-interface un
der your routing process you are not permitting hellos out that specific interf
ace which in turn will now allow any adjacency to form over that link.
Another thing just because you passive-interface for one routing process for ex
ample RIP this does not passive-interface for another routing protocol for exam
ple OSPF you might have running on that SAME interface.
HTH,
chris hugo
"Erick B." <erickbe@yahoo.com> wrote: Passive interface stops the router from
*sending*
broadcast/multicast routing updates. The router will
still *listen* to and accept routes unless they are
filtered out.
--- Hunt Lee wrote:
> Hey all,
>
> I'm trying to work out what does "passive-interface
> " do...
>
> RTA -- RTB -- RTC -- RTD - 156.26.32.0/24 &
> 156.26.33.0/24
>
>
> Both RTA, B & C are using OSPF.
> RTC also uses RIP v2, so it's an ASBR.
> And RTD uses RIPv2.
>
> RTC's Serial 0 interface is connecting to RTB &
> RTC's Serial 1 interface is connecting to RTD
>
> RTD advertise the 2 networks 156.26.32.0/24 &
> 156.26.33.0/24 with
> RIPv2.
>
> RTC is doing mutual redistribution, where the RIPv2
> is being
> redistributed into OSPF, and OSPF is being
> redistributed back into
> RIP.
>
> And there is a distribute-list at RTC to stop RTD to
> advertise any
> OSPF learned routes back into OSPF.
>
> router rip
> version 2
> redistribute ospf 3 metric 5
> network 10.0.0.0
> distribute-list 1 in Serial1
> no auto-summary
> !
> access-list 1 permit 156.26.32.0 0.0.1.255
>
> But I couldn't find the use of the
> "passive-interface" command.
>
> RouterC(config)#router rip
> RouterC(config-router)#passive-interface serial 0
>
> It just doesn't seems to do anything. With it or
> without it, my OSPF
> routers (RTA & RTB) can get the RIP routes and able
> to reach
> 156.26.32.0 & 33.0 network.
>
> Any ideas are welcome.
>
> H.
>
> http://digital.yahoo.com.au - Yahoo! Digital How To
> - Get the best out of your PC!
>
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