From: Chris Lewis (chrlewiscsco@yahoo.com)
Date: Fri Oct 21 2005 - 11:45:30 GMT-3
Hi,
I had difficulty following all the views expressed on this thread, so labbed it up to see if I could get what I thought was the desired behavior. The desired behavior being could I use the ip pim rp-announce-filter by itself to influence which rp is selected for which groups.
This is my topology
R3 R2 R4
\ | /
R1
|
R6
unicast and pim are setup with appropriate reachability and neighbor relationships.
R2 and R4 have loopbacks 192.168.2.2 and 192.168.4.4 respectively and are setup to be candidate RPs for the group 225.1.1.1 only
R3 is the mapping agent and I test my results by looking at the sho ip pim rp mapp output on R6
With no filters in place, R6 shows the following:
Router6#sho ip pim rp mapp
PIM Group-to-RP Mappings
Group(s) 225.1.1.1/32
RP 192.168.4.4 (?), v2v1
Info source: 192.168.3.3 (?), elected via Auto-RP
Uptime: 00:08:59, expires: 00:02:54
Router6#
This is as expected, as the highest IP address becomes the RP for the group. If I want to change the RP to be R2 instead without changing the configuration of R2 or R4, I place the following on R3.
access-list 1 permit 192.168.4.4
access-list 2 deny 225.1.1.1
access-list 2 permit any
!
ip pim rp-announce-filter rp 1 group 2
Then clear the rp mappings on R6 and see the following:
Router6#sho ip pim rp mapp
PIM Group-to-RP Mappings
Group(s) 225.1.1.1/32
RP 192.168.2.2 (?), v2v1
Info source: 192.168.3.3 (?), elected via Auto-RP
Uptime: 00:00:58, expires: 00:02:00
Router6#
This shows that I have been able to use the rp-announce-filter on the mapping agent to deny an RP for a group and change the RP selected for that group.
When I first configured this as the documentation suggests, I was not using deny statements in the access lists and could not influence RP selection.
Is this the consensus of how it should be working? Am I missing anything here? Doesn't this configuration have the same effect as using the priority option in the BSR configuration to influence which RP gest to be the RP for a group?
Chris
---------------------------------
Yahoo! FareChase - Search multiple travel sites in one click.
This archive was generated by hypermail 2.1.4 : Sun Nov 06 2005 - 22:00:52 GMT-3