From: Scott M. Livingston (scottl@sprinthosting.net)
Date: Wed Mar 26 2003 - 19:52:16 GMT-3
Good point on the HSRP thing; that would certainly be something to
watch.
The other school of thought would be a concern about covering to many
interfaces with OSPF, which most likely would not result in any problems
(unless a neighbor was actually established), but would certainly be a
misconfiguration in the event the Lab task told you to only configure
OSPF on certain interfaces.
I like the tight control method myself; both in my production network
and in the lab environment. I do at times like to use the mask approach
in production, especially if all my subnets are in the same chunk and I
don't want to type out 10 or more network statements.
Everyone needs to pick their own method based off what they feel most
comfortable w/ I guess.
Thanks,
scott
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Voss, David
Sent: Wednesday, March 26, 2003 2:19 PM
To: 'Jonathan V Hays'; 'Tim Fletcher'; 'Angelo De Guzman';
CCIELAB@groupstudy.com
Subject: RE: Defining OSPF Area
I've seen and heard plenty of examples using 0.0.0.0 mask but I'm
convinced
that it's worth the time to take a look at your interface mask and place
in:
0.0.0.3
0.0.0.255
or as appropriate...
The time spent in using non-0.0.0.0 masks outweighs the hour you might
spent
troubleshooting issues with 0.0.0.0 mask (i.e. later in the lab
implementing
hsrp then changing the ip on the interface or the forward address issue
on
Ethernet networks).
-----Original Message-----
From: Jonathan V Hays [mailto:jhays@jtan.com]
Sent: Wednesday, March 26, 2003 12:59 PM
To: 'Tim Fletcher'; 'Angelo De Guzman'; CCIELAB@groupstudy.com
Subject: RE: Defining OSPF Area
On page 295 of the "Cisco OSPF Command and Configuration Handbook" Bill
Parkhurst says:
"One problem that can arise when using a host address in the [OSPF]
network statement is if the IP address of the interface changes. If you
change the IP address of the Ethernet interface on Router A from
172.16.1.1 to 172.16.1.3, then the interface will no longer be enabled
for OSPF. You need to delete the network statement containing the host
router 172.16.1.1 and re-enter the network statement using the host
route 172.16.1.3."
His point is that using "network 172.16.1.0 0.0.0.255" avoids this minor
problem. When you change the interface IP address you will NOT have to
re-enter the network statement. With the /24 wildcard mask you will
*still* momentarily lose your OSPF neighbor connection on that interface
when you change the interface IP address - but it will automatically be
reestablished without needing to muck around with the OSPF network
command.
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
> Behalf Of Tim Fletcher
> Sent: Wednesday, March 26, 2003 10:35 AM
> To: Angelo De Guzman; CCIELAB@groupstudy.com
> Subject: Re: Defining OSPF Area
>
>
> Angelo,
>
> It is just 2 ways of representing it on the router, and is
> strictly a mater
> of personal preference. In fact you can configure two routers using
> different formats on each one, and as long as the numbers
> match, it will
> work. For example a router configured with area 1000 will
> work just fine
> with a router configured with area 0.0.0.3.232.
>
> Sometimes a dotted notation will be used in a hub and spoke
> topology, where
> each spoke is in a separate area. To simplify
> troubleshooting, you can use
> the same area number as the block of IPs assigned to that spoke.
>
> -Tim Fletcher
>
> At 10:25 PM 3/25/2003 -0800, Angelo De Guzman wrote:
> >Hi To All,
> > What is the best practice in computer the OSPF
> >area. Use 0 or 0.0.0.0. All routers are Cisco. Please enumerate the
> >advantage and desadvantage of using each. Specially in
> troubleshooting
> >and configuration wise?
> >Thanks in Advance,
> >Angelo
> >
> >__________________________________________________
> >Do you Yahoo!?
> >Yahoo! Platinum - Watch CBS' NCAA March Madness, live on
> your desktop!
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