From: Rich Collins (nilsi2002@gmail.com)
Date: Tue Oct 30 2007 - 15:40:42 ART
I looked into your question:
"Can I say that the simplest and straighforward solution is to define ACL on
R5 to permit groups 224-238?
By the way, can we use "deny" in the ACL for "ip pim send-rp-announce
group-list" command? How does the mapping agent respond to it?"
Answer:
I have my doubts about it. I have noticed in my multicast studying that the
access lists seem to be PERMIT only. I would be also interested in more
clarification.
It looks like you can include a deny only if you do not want sparse mode for
this range of groups (don't expect another rp via autorp to be able to take
over for this range).
Candidate R1
Rack1R1#sh access-lists 24
Standard IP access list 24
10 deny 238.0.0.0, wildcard bits 0.255.255.255
20 permit 224.0.0.0, wildcard bits 15.255.255.255
ip pim send-rp-announce Loopback2 scope 15 group-list 24
Candidate R5
Rack1R5#sh access-lists
Standard IP access list 24
10 permit 238.0.0.0, wildcard bits 0.255.255.255
ip pim send-rp-announce Loopback2 scope 15 group-list 24
--------------------------------------------------------------------------------------------------------------------------
Then on the mapping agent.
Rack1R4#sh ip pim rp mapping
PIM Group-to-RP Mappings
This system is an RP-mapping agent (Loopback2)
Group(s) 224.0.0.0/4
RP 192.168.1.1 (?), v2v1
Info source: 192.168.1.1 (?), elected via Auto-RP
Uptime: 00:03:28, expires: 00:02:29
Group(s) (-)238.0.0.0/8
RP 192.168.1.1 (?), v2v1
Info source: 192.168.1.1 (?), elected via Auto-RP
Uptime: 00:03:28, expires: 00:02:30
Rack1R4#
*Oct 29 11:51:04.212: Auto-RP(0): Received RP-announce, from 192.168.1.1,
RP_cnt 1, ht 181
*Oct 29 11:51:04.212: Auto-RP(0): Update (-238.0.0.0/8, RP:192.168.1.1),
PIMv2 v1
*Oct 29 11:51:04.216: Auto-RP(0): Update (224.0.0.0/4, RP:192.168.1.1),
PIMv2 v1
*Oct 29 11:51:04.220: Auto-RP(0): Received RP-announce, from 192.168.1.1,
RP_cnt 1, ht 181
*Oct 29 11:51:04.220: Auto-RP(0): Update (-238.0.0.0/8, RP:192.168.1.1),
PIMv2 v1
*Oct 29 11:51:04.224: Auto-RP(0): Update (224.0.0.0/4, RP:192.168.1.1),
PIMv2 v1
Rack1R4#
Here we see the second candidate but they aren't installed
*Oct 29 11:51:21.340: Auto-RP(0): Received RP-announce, from 192.168.5.1,
RP_cnt 1, ht 181
*Oct 29 11:51:21.344: Auto-RP(0): Received RP-announce, from 192.168.5.1,
RP_cnt 1, ht 181
Rack1R4#
*Oct 29 11:51:54.960: Auto-RP(0): Build RP-Discovery packet
*Oct 29 11:51:54.960: Auto-RP: Build mapping (224.0.0.0/4, RP:192.168.1.1),
PIMv2 v1,
*Oct 29 11:51:54.964: Auto-RP: Build mapping (-238.0.0.0/8, RP:192.168.1.1),
PIMv2 v1.
*Oct 29 11:51:54.968: Auto-RP(0): Send RP-discovery packet on
FastEthernet0/0 (1 RP entries)
*Oct 29 11:51:54.968: Auto-RP(0): Send RP-discovery packet on Serial1/0.45
(1 RP entries)
*Oct 29 11:51:54.972: Auto-RP: Send RP-discovery packet on Loopback2 (1 RP
entries)
I assume the entry for 238.0.0.0/8 is already filled in the mapping table -
even if it is a deny.
-Rich
On 10/30/07, hadek.el-ayachi@nsn.com <hadek.el-ayachi@nsn.com> wrote:
>
> Longest match has the same meaning as when looking for entry in ip
> routing table.
> The longest match is 239/8 in this case. So, MA receive two CRP
> announcements, one for 239/8 and other for 224/4. it starts by the
> longest match which is 239/8 ignoring 224/4.
>
>
> -----Original Message-----
> From: ext Gregory Gombas [mailto:ggombas@gmail.com]
> Sent: mardi 30 octobre 2007 16:46
> To: El Ayachi Hadek (NSN - MA/Rabat)
> Cc: ccielab@groupstudy.com
> Subject: Re: FW: Auto-RP : Multiple C-RPs for the same group
>
> By longest match do you mean advertise the group with /32?
>
> Would that be accomplished like this?
>
> access-list 1 permit 239.5.5.5 0.0.0.0
>
> On 10/30/07, hadek.el-ayachi@nsn.com <hadek.el-ayachi@nsn.com> wrote:
> > RP is selected based on the following criteria, respectively:
> > 1- Longest match
> > 2- low Priority
> > 3- high hash
> > 4- high Ip address
> > In case of AutoRP, this is equivalent to the 4th condition, provided
> > that there are many condidates for the same prefix (exact match)
> >
> > ________________________________
> >
> > From: ext Toh Soon, Lim [mailto:tohsoon28@gmail.com]
> > Sent: mardi 30 octobre 2007 15:21
> > To: El Ayachi Hadek (NSN - MA/Rabat)
> > Cc: ccielab@groupstudy.com
> > Subject: Re: Auto-RP : Multiple C-RPs for the same group
> >
> >
> >
> > Hi,
> >
> > Kindly correct me if I'm wrong.
> >
> > A Mapping Agent selects the RP for a given multicast group address
> > range(s) based on the candidate RPs' IP address. The highest candidate
>
> > RP IP address is selected.
> >
> > In other words, the tie-breaker is purely based on C-RP's IP address.
> >
> >
> > Thank you.
> >
> > B.Rgds,
> > Lim TS
> >
> >
> >
> >
> > On 10/30/07, hadek.el-ayachi@nsn.com <hadek.el-ayachi@nsn.com> wrote:
> >
> > The task is to make R5 RP for all but 239/8, so you should use
> > selective
> > acl denying 239/8.
> > Otherwise, the RP is selected based on longest match (before
> > prefering
> > low priority, high hash or high IP address)
> > All that I know!
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com ] On
> > Behalf Of
> > ext Toh Soon, Lim
> > Sent: mardi 30 octobre 2007 13:51
> > To: ccielab@groupstudy.com
> > Subject: Auto-RP : Multiple C-RPs for the same group
> >
> > Hi Group,
> >
> > I have the following Auto-RP scenario:
> >
> > R7
> > --
> > 1. C-RP for 239.0.0.0/8
> > 2. RP address 200.0.0.7
> >
> > R5
> > --
> > 1. Mapping agent
> > 2. C-RP for all groups except 239.0.0.0/8 3. RP address
> > 200.0.0.5
> >
> > I guess one way of configuring this is, we define an ACL on R5
> > that
> > matches groups 224 until 238 (summarizing whatever we can) and
> > let R5
> > announce this group-list.
> >
> > Another way I'm thinking of is, since R7's IP address is higher
>
> > than
> > R5's, I will configure R5 to announce, by default, all groups.
> > When R5
> > and R7 contend for group 239.0.0.0/8, R7 will win. R5 will be
> > RP for the
> > rest of the groups. In the end, this solution meets the task
> > requirement
> > and does not violate any rules but is it acceptable?
> >
> > Please share if you have other methods.
> >
> >
> > Thank you.
> >
> > B.Rgds,
> > Lim TS
> >
> >
> >
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