Comments on: How do prefix-lists work? http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/ Helping you become a Cisco Certified Internetwork Expert Tue, 07 Feb 2012 01:32:29 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Brian McGahan, CCIE #8593 http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-474011 Brian McGahan, CCIE #8593 Mon, 14 Nov 2011 21:04:45 +0000 http://blog.ine.com/?p=9#comment-474011 Correct. Correct.

]]> By: Mark http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-465966 Mark Wed, 09 Nov 2011 21:22:05 +0000 http://blog.ine.com/?p=9#comment-465966 So if I used to do a reverse mask like: permit ip 192.168.87.0 0.0.0.3 any It would now be: permit 192.168.87.0/30 le 32 ? thanks, Mark So if I used to do a reverse mask like:
permit ip 192.168.87.0 0.0.0.3 any

It would now be:
permit 192.168.87.0/30 le 32 ?

thanks,

Mark

]]> By: Sumit http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-463897 Sumit Tue, 08 Nov 2011 12:04:03 +0000 http://blog.ine.com/?p=9#comment-463897 Most concise and informative article ever on prefix-list. Thanks a lot. Most concise and informative article ever on prefix-list.
Thanks a lot.

]]> By: Brian McGahan, CCIE #8593 http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-428365 Brian McGahan, CCIE #8593 Fri, 07 Oct 2011 13:45:05 +0000 http://blog.ine.com/?p=9#comment-428365 172.16.1.32/28 172.16.1.32/28

]]> By: Happy http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-428016 Happy Fri, 07 Oct 2011 07:38:25 +0000 http://blog.ine.com/?p=9#comment-428016 What should be the prefix list to permit prefix 172.16.1.32 255.255.255.240 ? What should be the prefix list to permit prefix 172.16.1.32 255.255.255.240 ?

]]> By: rshah.ec http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-384064 rshah.ec Tue, 23 Aug 2011 18:40:46 +0000 http://blog.ine.com/?p=9#comment-384064 What does following prefix list mean? ip prefix-list LIST permit 0.0.0.0/32 What does following prefix list mean?

ip prefix-list LIST permit 0.0.0.0/32

]]> By: Ciprian http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-232083 Ciprian Sun, 06 Mar 2011 11:13:57 +0000 http://blog.ine.com/?p=9#comment-232083 Thank you Brian ! Great explanations ! Thank you Brian ! Great explanations !

]]> By: Brian McGahan, CCIE #8593 http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-195117 Brian McGahan, CCIE #8593 Tue, 18 Jan 2011 18:39:12 +0000 http://blog.ine.com/?p=9#comment-195117 Prefix-lists, like access-lists, have implicit deny at the end. If you leave out the second sequence all routes will be denied. Prefix-lists, like access-lists, have implicit deny at the end. If you leave out the second sequence all routes will be denied.

]]> By: Peter http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-194582 Peter Mon, 17 Jan 2011 21:00:44 +0000 http://blog.ine.com/?p=9#comment-194582 Very good article... I have been going through some sample configuration(given below) where prefix-list has been used to prevent default route out of the interface. My question is do we really need both these prefix-list statements? Can't we omit the second line in the prefix-list to acheive this purpose? ip prefix-list NODEF_OUT seq 5 deny 0.0.0.0/0 ip prefix-list NODEF_OUT seq 10 permit 0.0.0.0/0 le 32 router eigrp 10 network 1.2.3.0 0.0.0.255 distribute-list prefix NODEF_OUT out Tunnel0 Very good article…
I have been going through some sample configuration(given below) where prefix-list has been used to prevent default route out of the interface. My question is do we really need both these prefix-list statements? Can’t we omit the second line in the prefix-list to acheive this purpose?

ip prefix-list NODEF_OUT seq 5 deny 0.0.0.0/0
ip prefix-list NODEF_OUT seq 10 permit 0.0.0.0/0 le 32

router eigrp 10
network 1.2.3.0 0.0.0.255
distribute-list prefix NODEF_OUT out Tunnel0

]]> By: Nadeem Rafi http://blog.ine.com/2007/12/26/how-do-prefix-lists-work/#comment-57848 Nadeem Rafi Sat, 25 Jul 2009 09:28:24 +0000 http://blog.ine.com/?p=9#comment-57848 Quite good and helpful information. Quite good and helpful information.

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