From: Brian McGahan (brian@xxxxxxxxxxxxxxx)
Date: Mon Aug 05 2002 - 18:04:18 GMT-3
Jeremy,
A common misconception about the 'network' statement is that it
means what networks you are advertising. This is only true for BGP.
The network statement in IGP actually means which interfaces you are
running the protocol on. With a classful protocol such as RIP or IGRP
(and EIGRP pre 12.1), there is not much of a distinction here, since you
can only use classful network statements. However, with EIGRP and OSPF,
you can add a wildcard to distinguish which interfaces are
participating. Take the following OSPF config for example.
Router ospf 1
Network 1.2.3.4 0.0.0.0 area 0
This means that the interface 1.2.3.4 is participating in area 0.
Router ospf 1
Network 1.2.3.4 0.0.0.255 area 0
This means that all interfaces within the range of 1.2.3.0 - 1.2.3.255
are participating in area 0.
Router ospf 1
Network 0.0.0.0 255.255.255.255 area 0
This means that all interfaces are participating in area 0.
The wildcard that accompanies the network statement has nothing
to do with the subnet mask of the interface. It is an address and
wildcard pair that specifies which interfaces are participating in the
protocol.
In other words, you are advertising 1.1.1.0/24, 1.1.1.1/32 does not come
into play in this situation at all.
HTH
Brian McGahan, CCIE #8593
Director of Design and Implementation
brian@cyscoexpert.com
CyscoExpert Corporation
Internetwork Consulting & Training
http://www.cyscoexpert.com
Voice: 847.674.3392
Fax: 847.674.2625
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Wright, Jeremy
> Sent: Monday, August 05, 2002 3:29 PM
> To: 'ccielab@groupstudy.com'
> Subject: ospf 0.0.0.0 wildcard mask
>
> if i have 1.1.1.1/24 defined on eth0, and advertise it in area 0=
1.1.1.1
> 0.0.0.0 area 0, that enables that /32 interface in the ospf process.
> should
> i be able to get to any ip's within the /24 on the interface besides
> 1.1.1.1? i dont believe i should but i just want to clear it up. TIA!
>
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> ************************
> Jeremy Wright
> Network Analyst
> Archer Daniels Midland
> ja_wright@admworld.com
> (217)451-4063
>
> ************************
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