From: Voss, David (dvoss@heidrick.com)
Date: Wed Mar 26 2003 - 17:18:30 GMT-3
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
> >
> >__________________________________________________
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> your desktop!
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