But the first two do not have /24 masks. The second one has a /25
On Thu, Apr 15, 2010 at 10:19 AM, Fabio Mendes <[email protected]> wrote: > Thanks you guys for all the answers. > I know this is a competitor's content (I'm sorry if I'm breaking ML's > rules), but after reading > this: http://www.routerie.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=50;t=001706 (the > second post) > I finally understood prefix-list's logic. > So here's the solution: > I'm receiving three > prefixes: 10.252.52.0/24, 10.252.60.0/25 and 10.252.114.0/24, and I'd like > to filter (i.e. I dont to announce these networks to my neighbor) only the > first two using a single prefix-list statement. > The catch about prefix-lists is that when they're used WITH an le or ge > statement, the number after the network (/whatever), becomes the number of > bits matched AND the numbers between le and/or ge statements become the > length of subnet mask to be matched > So using this logic the best answer would be: > ip prefix-list ACL-DENY-SOME seq 5 deny 10.252.48.0/20 ge 24 le 24 > ip prefix-list ACL-DENY-SOME seq 10 permit 0.0.0.0/0 le 32 > So I'm, not announcing 10.252.[48-63].0 networks (which includes > 10.252.52.0, 10.252.60.0 among others), as long as they are received with an > EXACT /24 netmask. > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > -- Regards, Joe Astorino - CCIE #24347 Sr. Technical Instructor - IPexpert Mailto: [email protected] Telephone: +1.810.326.1444 Live Assistance, Please visit: www.ipexpert.com/chat eFax: +1.810.454.0130 IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, Audio Tools, Online Hardware Rental and Classroom Training for the Cisco CCIE (R&S, Voice, Security & Service Provider) certification(s) with training locations throughout the United States, Europe, South Asia and Australia. Be sure to visit our online communities at www.ipexpert.com/communities and our public website at www.ipexpert.com _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
