RE: Use of "ip pim rp-announce-filter"

From: Lee Donald (Lee.Donald@t-systems.co.uk)
Date: Thu Oct 20 2005 - 12:36:40 GMT-3


Hi Simon,

Now lab it up using specific groups like 229.29.29.29 - and - 233.33.33.33,

What do you get now ?

-----Original Message-----
From: simon hart [mailto:simon@harttel.com]
Sent: 20 October 2005 16:13
To: Lee Donald; The Great Ryan; Cisco certification
Subject: RE: Use of "ip pim rp-announce-filter"

Hi Lee,

Have just labbed this up without the rp-announce-filter. As you will see
this command is not needed unless you wish to stop certain RP's announcing
for defined groups.

R2 is candidate RP for 229.0.0.0/8. R2 is also the mapping agent for the
MCAST domain

ip pim send-rp-announce Loopback0 scope 16 group-list 50
Standard IP access list 50
    10 permit 229.0.0.0, wildcard bits 0.255.255.255

R3 is RP for group 233.0.0.0/8

ip pim send-rp-announce Loopback0 scope 16 group-list 50
Standard IP access list 50
    10 permit 233.0.0.0, wildcard bits 0.255.255.255

Here is the result of the sho ip pim rp map on each router

Rack1R3#sh ip pim rp map
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)

Group(s) 229.0.0.0/8
  RP 150.1.2.2 (?), v2v1
    Info source: 150.1.2.2 (?), elected via Auto-RP
         Uptime: 00:12:35, expires: 00:02:09
Group(s) 233.0.0.0/8
  RP 150.1.3.3 (?), v2v1
    Info source: 150.1.2.2 (?), elected via Auto-RP
         Uptime: 00:12:10, expires: 00:02:09
Rack1R3#

AND

Rack1R2#sh ip pim rp map
PIM Group-to-RP Mappings
This system is an RP (Auto-RP)
This system is an RP-mapping agent (Loopback0)

Group(s) 229.0.0.0/8
  RP 150.1.2.2 (?), v2v1
    Info source: 150.1.2.2 (?), elected via Auto-RP
         Uptime: 00:13:04, expires: 00:02:55
Group(s) 233.0.0.0/8
  RP 150.1.3.3 (?), v2v1
    Info source: 150.1.3.3 (?), elected via Auto-RP
         Uptime: 00:12:39, expires: 00:02:26
Rack1R2#

Here are some debugs from R2

Rack1R2#Rack1R2#
Mar 2 07:56:06.161: Auto-RP(0): Build RP-Discovery packet
Mar 2 07:56:06.165: Auto-RP: Build mapping (229.0.0.0/8, RP:150.1.2.2),
PIMv2 v1,
Mar 2 07:56:06.169: Auto-RP: Build mapping (233.0.0.0/8, RP:150.1.3.3),
PIMv2 v1.
Mar 2 07:56:06.173: Auto-RP(0): Send RP-discovery packet on Ethernet0 (2 RP
entries)
Mar 2 07:56:06.177: Auto-RP(0): Send RP-discovery packet on Serial0 (2 RP
entries)
Mar 2 07:56:06.181: Auto-RP: Send RP-discovery packet on Loopback0 (2 RP
entries)
Rack1R2#Rack1R2#
Mar 2 07:56:19.193: Auto-RP(0): Build RP-Announce for 150.1.2.2, PIMv2/v1,
ttl 16, ht 181
Mar 2 07:56:19.197: Auto-RP(0): Build announce entry for (229.0.0.0/8)
Mar 2 07:56:19.201: Auto-RP(0): Send RP-Announce packet on Ethernet0
Mar 2 07:56:19.205: Auto-RP(0): Send RP-Announce packet on Serial0
Mar 2 07:56:19.209: Auto-RP: Send RP-Announce packet on Loopback0
Mar 2 07:56:19.213: Auto-RP(0): Received RP-announce, from 150.1.2.2,
RP_cnt 1, ht 181
Mar 2 07:56:19.217: Auto-RP(0): Update (229.0.0.0/8, RP:150.1.2.2), PIMv2
v1

-----Original Message-----
From: Lee Donald [mailto:Lee.Donald@t-systems.co.uk]
Sent: 20 October 2005 15:41
To: simon hart; Lee Donald; The Great Ryan; Cisco certification
Subject: RE: Use of "ip pim rp-announce-filter"

Simon,

If you want to restrict the mapping agent from advertising the RP out for
other groups you will have to use a filter on the announce, and a filet on
the mapping agent.
These 2 filters have to be the same obviously. Lab it up, you'll see.
This was also explained to me on a multicast class from I.E by Brain M.

I will lab it up again but I'm fairly sure.

Regards

Lee.

-----Original Message-----
From: simon hart [mailto:simon@harttel.com]
Sent: 20 October 2005 15:18
To: Lee Donald; The Great Ryan; Cisco certification
Subject: RE: Use of "ip pim rp-announce-filter"

Lee,

I think you will find that you do not need the rp-announce-filter on the
mapping agent. The fact the the RP is announcing through a group list is
enough. If you look at Ryan's show rp map statement below you will see that
R2 has been elected for just 224.0.0.0/5 via autorp. If the group-list was
not working or configured this would be 224.0.0.0/4

Say for instance you had two RP's reporting that they could map to the same
group addresses you can use the rp-announce-filter on the mapping agent to
determine which RP to use and which to not.

Simon

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Lee Donald
Sent: 20 October 2005 10:01
To: The Great Ryan; Cisco certification
Subject: RE: Use of "ip pim rp-announce-filter"

Ryan,

You need a group list on the RP announce, and also a filter on the mapping
agent for this situation.

I don't know why Cisco have implemented this like this, but for the RP to be
just for 2 groups and nothing else, 2 filters must be used. One on the RP
and the other on the mapping agent.

Regards

Lee.

-----Original Message-----
From: The Great Ryan [mailto:pv.ryan@gmail.com]
Sent: 19 October 2005 17:21
To: Cisco certification
Subject: Use of "ip pim rp-announce-filter"

Hi, Group,

---(e0)R1(s1)------(s1)R2(e0)---

I setup a lab for RP Filtering by using Auto-RP
R1 acts as RP announcement
R2 acts as mapping agent

In R1, I already limit the use of RP by access-list 11 (i.e. 224.0.0.0
7.255.255.255)
Is it necessary to also set a RP-filter on the mapping agent to limit
the use of RP?
I have no idea where I should put "ip pim rp-announce-filter" in
multicast network. Thanks !

Ryan
=======================================
R2#show ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP-mapping agent (Loopback0)

Group(s) 224.0.0.0/5
  RP 172.16.1.1 (?), v2v1
    Info source: 172.16.1.1 (?), elected via Auto-RP
         Uptime: 00:20:11, expires: 00:02:48

================R1 Config========================

interface Loopback 0
 ip address 172.16.1.1 255.255.255.0
interface serial 1
 ip pim sparse-dense-mode
!
ip pim send-rp-announce Loopback0 scope 15 group-list 11
access-list 11 permit 224.0.0.0 7.255.255.255
================R2 Config========================
R2

interface s1
 ip pim sparse-dense-mode
!
ip pim send-rp-discovery Loopback0 scope 15
ip pim rp-announce-filter rp-list 1 group-list 11
access-list 1 permit 172.16.1.1
access-list 11 permit 224.0.0.0 7.255.255.255



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