Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

prefix-list vs access-list and these two articles

I have read in CCNP curriculum that Cisco says :

" Use prefix lists as an alternative to access lists with many BGP route filtering commands. The advantages of using prefix lists rather than access lists include the following :

1- Significant performance improvement in loading and route lookup of large lists.

2- Support for incremental updates. Filtering by way of extended access lists does not support incremental updates.

3- A more user friendly command-line interface.

4- Greater flexibility ".

But when I read the article below , I could not figure out what does he mean :

" Unlike the IP access-list, which was designed to match traffic, the IP prefix-list was designed specifically with network reachability information in mind ".

Regards

2 ACCEPTED SOLUTIONS

Accepted Solutions
Cisco Employee

Re: prefix-list vs access-list and these two articles

What this article means is that the prefix-list would be used at the control plane level rather than the forwarding plane level.

For instance you wouldn't use a prefix-list to filter traffic (forwarding plane) as you do with an ACL. The prefix-list is mainly used for route filtering (control plane).

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
Hall of Fame Super Silver

Re: prefix-list vs access-list and these two articles

This link is to a good article by Russ White in the Internet Protocol Journal which includes some discussion of control plane and data plane (forwarding plane). I hope that it will help you to understand these concepts.

http://www.cisco.com/web/about/ac123/ac147/archived_issues/ipj_7-1/high_availability_routing.html

HTH

Rick

4 REPLIES
Cisco Employee

Re: prefix-list vs access-list and these two articles

What this article means is that the prefix-list would be used at the control plane level rather than the forwarding plane level.

For instance you wouldn't use a prefix-list to filter traffic (forwarding plane) as you do with an ACL. The prefix-list is mainly used for route filtering (control plane).

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
New Member

Re: prefix-list vs access-list and these two articles

((control plane level rather than the forwarding plane level)).

Thanks hritter, could you kindly explain it with more details, because I did not get what is the exact difference, between the control level and the forwarding level ?

Regards

Hall of Fame Super Silver

Re: prefix-list vs access-list and these two articles

This link is to a good article by Russ White in the Internet Protocol Journal which includes some discussion of control plane and data plane (forwarding plane). I hope that it will help you to understand these concepts.

http://www.cisco.com/web/about/ac123/ac147/archived_issues/ipj_7-1/high_availability_routing.html

HTH

Rick

New Member

Re: prefix-list vs access-list and these two articles

Thanks Rick for this link.

660
Views
5
Helpful
4
Replies