From: Kenneth Wygand (KWygand@customonline.com)
Date: Tue Sep 30 2003 - 11:18:30 GMT-3
Cristian is correct. My only "change" is I prefer to use .255 in the
last octet of my subnet mask for the matching criteria - Cristian's
answer will only work for the NETWORK addresses, and that is making the
assumption of a /24 mask.
If the question specifically states to block those "networks" or those
"addresses" specifically, then Cristian's answer is 100% correct,
possibly even more correct than my answer. However, if I'm using this
access list to filter routes, if any of those networks are subnetted
further at some point, or if the /32 host routes are advertised for
specific interfaces, using "x.x.x.0" for the subnet mask of the access
list will not cover those cases, while "x.x.x.255" will.
I guess it's on a case-by-case basis. Once again, ask the proctor!
(Learn from my mistakes :-P)
Kenneth E. Wygand
Systems Engineer, Project Services
CISSP #37102, CCNP, CCDP, MCP 2000, CNA 5.1, Network+, A+
Custom Computer Specialists, Inc.
"It's not just about ending up where you want to be, it's about making
the most of the trip there."
-Anonymous
-----Original Message-----
From: Cristian Henry H [mailto:chenry@reuna.cl]
Sent: Tuesday, September 30, 2003 10:03 AM
To: Casey, Paul (6822)
Cc: ccielab@groupstudy.com
Subject: Re: Access list filter in the shortest lines possible.
I got the following one:
access-list 10 permit 100.0.33.0 27.55.94.0
"Casey, Paul (6822)" ha escrito:
>
> > Hello,
> >
> > For example, say we are asked to filter the following routes using
the
> > shortest nuber of lines possible
> >
> > 102.17.63.0
> > 126.22.61.0
> > 111.22.57.0
> > 125.33.101.0
> >
> > Can someone tell me the best access list to use to filter these
networks.
> >
> > Thanks in advance.
> > Kind regards.
> >
> >
> >
> >
>
>
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