From: jonatale@xxxxxxxxxxxxx
Date: Thu Aug 16 2001 - 01:48:51 GMT-3
i always use 0.0.0.0, less thinking, less typing, less errors
i suppose on a big rtr you could "config-summarize" with 0.0.0.255 or 0.0.15.25
5
etc
also if all you have is ospf on the router then 0.0.0.0 0.0.0.0 is quick and
dirty and works
any comments?
Monty.Majszak@Level3.com wrote:
> Just out of curiosity, Yves, you said you know of problems w/ using the
> 0.0.0.0 wildcard mask. Peter, you stated, "I personally use the direct mask
> of 0.0.0.0 for all network statements." Can you guys clearify this? How
> much/how long have you been using the 0.0.0.0 Peter?
>
> P.S. in the real world, when would you want to set your network type to
> "non-broadcast" when doing the whole OSPF over Frame-relay fully-meshed
> thing?
>
> -Monty
>
> -----Original Message-----
> From: Yves Fauser [mailto:Yves@Fauser.de]
> Sent: Wednesday, August 15, 2001 12:57 PM
> To: Jeffrey Levine
> Cc: ccielab@groupstudy.com
> Subject: Re: router configs/OSPF - interfaces or entire networks?
>
> Hi Jeffrey,
>
> If you want to take an Interface into ospf it doesn't matter which of the
> statement you use.
> But be aware of the consequences that the 0.0.0.0 wildcard mask has, it
> changes the forwarding address in the database.
> To be short if you use the 0.0.0.0 Mask the forwarding address will be
> 0.0.0.0
> in the LSA. If you take 0.0.0.255 the forwarding address will be the address
> of the next hop. You can have various Problems with 0.0.0.0 or next hop
> depending on the topology. Another thing is that there is a Bug in all
> versions when redistributing ospf into RIP.
>
> I'll send some links later.
>
> Yves
>
> Jeffrey Levine wrote:
>
> > I have noticed in some lab scenarios that when the instructions say that a
> > router interface should be advertised in a routing protocol, the labs
> > sometimes advertise only the interface, othertimes an entire subnet.
> >
> > For example, let's say it's an ethernet interface with address
> > 192.168.1.1/24 being advertised under OSPF. I've seen the following:
> >
> > router ospf 64
> > net 192.168.1.1 0.0.0.0 area 0
> >
> > or
> >
> > router ospf 64
> > net 192.168.1.1 0.0.0.255 area 0
> >
> > I wouldn't be concerned if there were some consistency. I've seen the lab
> > instructions state "interface" and then seen the entire network advertised
> > and vice-versa.
> >
> > Any thought?
> >
> > Jeffrey S. Levine
> >
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