From: Ben Rife (brife@xxxxxxxxxx)
Date: Mon May 24 1999 - 22:26:13 GMT-3
53 days left for me....
To answer the original question
I would go ahead and configure L0... interfaces because of the stability
involved. You may also have to run BGP on a router which is also running
OSPF, in this case, I definitely would want to use L0.. interfaces. I have
found that the advantages outweigh the disadvantages in my studies.
About the "ip ospf net point" comand:
Actually from my studies, this command.....ip ospf network point-to-point
is used when doing OSPF over Frame, because there is a problem with
mismatched network types (i.e., timers).
For example, when OSPF is configured on Ethernet, the network type is
BROADCAST, when OSPF is configured on an NBMA interface, the type is
non-broadcast, etc.
This creates a problem when setting up OSPF, the solution is to make all
OSPF interfaces the same.
I prefer to make all of my OSPF interfaces BROADCAST type. This is done
with the interface configuration command: ip ospf network broadcast.
Hope this helps, If you would like to discuss this further, let me know.
Caslow's BRS book does a great job of explaining this.
Regards,
Benjy Rife
MCSE, CNE, CCIE Candidate
brife@bignet.net
----- Original Message -----
From: Scott Morris <SMorris@tele-tech.com>
To: 'Nentarz, Dave' <Dave.Nentarz@compaq.com>; 'Brian Van Benschoten'
<brian.vanbenschoten@inacom-msn.com>; <ccielab@groupstudy.com>
Sent: Monday, May 24, 1999 7:11 PM
Subject: RE: OSPF and virtual links
> Ummmm.... All that statement does (as far as i'm aware) is change the
> timers of the OSPF process on that interface... If you want to advertise
a
> loopback any way other than /32, you'll need to do redistribute connected,
> and possibly use a route map to pull that route through (ie. don't add
that
> network directly into the OSPF process).
>
> Scott Morris, MCSE, CNE (3.x), CCDA, CCIE #4713
> smorris@tele-tech.com
>
>
> -----Original Message-----
> From: Nentarz, Dave [mailto:Dave.Nentarz@compaq.com]
> Sent: Monday, May 24, 1999 10:20 AM
> To: 'Brian Van Benschoten'; ccielab@groupstudy.com
> Subject: RE: OSPF and virtual links
>
>
> I remember seeing a tech tip regarding this.
>
> Configure this under (loopback) interface mode:
> ip ospf network point-to-point
>
> This will make OSPF advertise your loopback interface as the network or
> subnet it's mask defines, rather than the /32 host route.
>
> I tried searching CCO docs for this to find which IOS level this first
> appeared in as a feature, but couldn't find anything on it..I'll keep
> looking.. try it in your lab and let me know if it works.
>
> Dave
>
> -----Original Message-----
> From: Brian Van Benschoten [mailto:brian.vanbenschoten@inacom-msn.com]
> Sent: Sunday, May 23, 1999 12:55 PM
> To: ccielab@groupstudy.com
> Subject: OSPF and virtual links
>
>
> I set up a lab test using virtual links. I used loopback interfaces
with
> high ip numbers) on both the routers that the vitural link connected. I
did
> this for stability and the fact the one of the routers had an ISDN dial
> backup link with a higher IP address than the other interaces. This is
the
> method most people recommend to do in the field. I realized that the
> loopbacks must be reachable from both routers in order to establish the
> virtual link. (the virtual link command points to the ROUTER ID, not an
> interface) so i included the loopbacks in the routing protocol. This got
me
> thinking about the CCIE lab
>
> A question regarding the CCIE lab exam..... I've had people tell me not
to
> do anything extra / more than is asked for during the lab. People have
told
> me that at the end of a section where different ip routing protocols /
> redistribution are used, all routers should be able to ping all other
> interfaces. Does this mean the "extra" interfaces i created to do a task
?
>
> If i include my loopback interfaces in whatever area my router is in,
using
> the network command; OSPF advertises loopback interfaces as /32. This
mask
> wont redistribute into classfull routing protocols like IGRP. I could run
> the loopbacks in a seperate area an use the "area range" to summarize
those
> addresses to match whatever subnet nask the classful protocol needed. But
> then am I supposed to create more OSPF areas than what the lab required ?
I
> could redistribute connected into OSPF but then the routes show up as
> external ?
>
> anyone see where I'm going with this ? Any opinions?
>
>
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