From: David H. Brown (DHBrown@xxxxxxxxxxxx)
Date: Fri Apr 21 2000 - 19:01:04 GMT-3
Derek is on the right track, but didn't mention a few details: You also have
to configure the priority such that the R1 is higher than R2 (say set R1 to
105, default for R2 will be 100), and the decrement value on the tracked
interface (default is 10) is high enough to allow R2 to take over if the
subinterface goes down. Also preempt must be on. This is off the top of my
head because I just happened to read the CiscoPress Case Studies book
chapter on HSRP this afternoon. :)
Certainly a fair question, Greg. IMHO, anyone who ridicules anyone here
should be removed from the list! And remember: The only dumb question is
the one nobody asked...
David
(RTP Lab 6/15)
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Derek Small (Fuse)
Sent: Friday, April 21, 2000 1:39 PM
To: LASSERRE Grégory; ccielab groupstudy
Subject: Re: Challenge : HSRP
If you can't ask a basic question here without getting ridiculed, then the
group is not what it was meant to be, (IMHO) Everyone of us has gone out
and looked up questions posted here that we probably should know but don't.
To answer your question, I think you want to use the "track interface"
option for HSRP. This allows you to change your HSRP active router based on
the status of an entirely different interface. This would only work on
Frame if you use sub-interfaces (just like backup interface requires subs
also).
Note:
It was recently pointed out to me, that although this is required for HSRP
to actually failover, it would not be necessary for network functionality.
When the frame link fails, OSPF will reconverge and R1 will begin sending
traffic over it's Ethernet port to R2. So even if R1 remains the active
router, it will issue an ICMP redirect and send traffic to R2 which will get
the traffic out. Be careful if you just use pings to test this. I have not
had time to test this, but the convergence times are probably not all that
dissimilar. Of course this is assuming you are running OSPF on the Ethernet
segment as well.
Someone please correct me if I'm wrong.
Derek Small
dwsmall@fatkid.com
----- Original Message -----
From: LASSERRE Grégory <gregory.lasserre@arche.fr>
To: ccielab groupstudy <ccielab@groupstudy.com>
Sent: Friday, April 21, 2000 11:56 AM
Subject: Challenge : HSRP
>
> Hi guys,
>
> I've got a challenging question i worked on last week regarding HSRP.
> The solution is not so trivial, and it took me a while to find the answer
> (so i hope you won't find the solution too quickly ;o)
>
> Just let's go :
>
> R1,R2, and R3 routers are full-meshed over FR,
> using point-to-multipoint interfaces.
>
> R1 and R2 are also connected via Ethernet.
> R3 has an LAN interface (Eth, or Token. As you wish)
>
> You are running HSRP between R1 and R2 ; and R1 is your Active router by
> default.
>
> What you want to do is to configure the routers so that
> R2 becomes the Active router IF and ONLY IF the DLCI between R1 and R3
fall
> down.
>
> Note: You have to run OSPF on the FR cloud (R1, R2, R3 are in Area 0)
>
> Good luck,
> and please don't ridiculate me finding the solution in 3 minutes ;o)
>
> Cheers.
> Greg.
>
> ------------------------------------------------------------------------
> Gregory LASSERRE Tel. : +33 1 69 18 98 53
> Network Engineer Fax : +33 1 69 28 55 01
> ARCHE Groupe SIEMENS Std : +33 1 69 18 32 32
> FRANCE
>
> E-mail : gregory.lasserre@arche.fr
> ------------------------------------------------------------------------
>
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