From: Truman, Michelle, NTCOM (mtruman@xxxxxxx)
Date: Thu Sep 28 2000 - 11:28:21 GMT-3
I'll give you an example of community attribute use. Many ISP's follow the
recommendations for RFC 1998. The ISP will set up a filter which looks for
specific community attributes and uses them as a flag to trigger other
actions. In the RFC1998 case, the ISP sets up several communities to signify
specific local preference attributes. (Remember, local-preference does not
transit between AS'). The customer can signal the ISP to raise or lower
local preference to trigger exit preference by setting the community on
particular route announcements.
The well known communities such as no-export and no-advertise also trigger
behavior on the part of the ISP.
Michelle Truman, CCNP
Sr. Technical Consultant
AT&T Data and Internet Services
w 612-376-5137
vo 651-917-8104
Fax 720-221-8535
mtruman@att.com
-----Original Message-----
From: mark salmon [mailto:masalmon@cisco.com]
Sent: Thursday, September 28, 2000 11:14 AM
To: damien
Cc: ccielab@groupstudy.com
Subject: Re: BGP community attribute
OK, so the community Attribute is set for 300, what is the point? What
effect does setting that attribute have on routing?
damien wrote:
>
> I am not sure about the last statement, but basically, any ip prefix in
the
> update ( access-list 1 permit 0.0.0.0 255.255.255.255) sent to 2.2.2.2
will
> have the community attribute field set to 300......I am not sure what he
is
> talking about any "Access list 1 denies any update for network 170.10.0.0
> and permits updates for any other network.".......to me he/ she is talking
> b0!!03..........
Mark Salmon
Network Support Engineer
SBC OP HQ
Cisco Systems Inc
8735 W. Higgins Road
Suite 300
Chicago IL 60631
Phone:773-695-8235
Pager:800-365-4578
email: masalmon@cisco.com
Empowering The Internet Generation.
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:25:08 GMT-3