04-20-2013 03:56 AM - edited 03-04-2019 07:39 PM
Hello,
I have 4 sites, 2 of them will be producing multicast streams (at the moment), but currently at one of the sites is the RP. This may cause us problems because of unecessary traversal of the links for this kind of traffic. Each site has a pair of ASR 1K's that are doing the WAN aggregation - all point-to-point circuits. One of them will be the RP.
How do I go about splitting this up so I have one RP that looks after a certain multicast address group for one site, and another RP that is taking care of another group?
I also read about multicast domains, I was thinking, would it be better if I split the 4 in to their separate multicast domains, have one RP per site and have some sort of peerings between all sites, in the case that someone is interested in the multicast traffic from other sites?
Any sort of idea's suggestions and config examples would be much appreciated.
tia
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04-20-2013 07:03 AM
//How do I go about splitting this up so I have one RP that looks after a certain multicast address group for one site, and another RP that is taking care of another group?//
ip multicast-routing
ip pim RP-address 1.1.1.1 2
ip pim RP-address 2.2.2.2 3
access-list 2 permit 224.1.1.1
access-list 2 permit 224.1.1.2
access-list 2 permit 224.1.1.3
access-list 3 permit 224.2.2.2
access-list 3 permit 224.2.2.3
access-list 3 permit 224.2.2.4
(http://www.cisco.com/en/US/tech/tk828/technologies_tech_note09186a0080094821.shtml#autowithone)
I have always been fuzzy on the meaning of multicast domains. I always thought that having separate "multicast domains" meant you could re-use the same multicast address, and it wouldn't conflict with your other sites.
04-20-2013 07:52 AM
Hi Bilal,
I think I'd use an IP Anycast RP approach having an Anycast RP in each site and the other multicast routers in your environment configured with a static RP of the Anycast RP address. To finish things off, you peer the two Anycast RPs using Multicast Source Discovery Protocol (MSDP).
This solution would give you load sharing of the registrations across the two RPs (assuming sources in both sites), the RP is in the same site as the sources/receivers and you get rapid convergence i.e., the speed of your IGP, in the event of a failure of one of the devices acting as the RP.
There's a more detailed explanation and configuration example in the Anycast RP white paper.
Regards
04-20-2013 08:57 AM
Hey Steve/Gabriel,
Thank you for this information, been great helping me understand a bit more about multicast. Have a final question... Am i able to use a combination of both? I do think the anycast RP solution with msdp per site is an elegant way of setting things up.
Example: lets say I have site A and site B
Site A & B both have:
ASR1001-01 and 02 will have an MSDP peering between each other, sharing the same RP address
Also filtered by acls to specify for which address group the RP should be for?
They all will know about the different multicast sources right?
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04-21-2013 10:23 AM
Hello Bilai
To define specific source m/c see link below
http://www.cisco.com/en/US/docs/ios-xml/ios/ipmulti_igmp/configuration/xe-3s/imc_ssm_map.html
Res
Paul
Sent from Cisco Technical Support iPad App
04-22-2013 01:03 AM
Hello Bilal,
you can achieve to use MSDP with source active messages filtering over the MSDP sessions
a) filtering inbound
see
http://www.cisco.com/en/US/docs/ios-xml/ios/ipmulti/command/imc_i2.html#wp5749501050
ip msdp [ vrf vrf-name ] filter-sa-request { peer-address | peer-name } [ list access-list ]
>> By default, the router honors all SA request messages from peers. If this command is not configured, all SA request messages are honored. If this command is configured but no access list is specified, all SA request messages are ignored.
in this way you filter inbound on received SA messages from MSDP peer
b) filtering outbound
Alternatively you can filter out to the neighbor using
http://www.cisco.com/en/US/docs/ios-xml/ios/ipmulti/command/imc_i2.html#wp3266518951
ip msdp [ vrf vrf-name ] sa-filter out { peer-address | peer-name } [ list access-list-name ] [ route-map map-name ] [ rp-list { access-list-range | access-list-name } ] [ rp-route-map route-map reference ]
c) ip msdp redistribute
There is a third option that is ip msdp redistribute
ip msdp [ vrf vrf-name ] redistribute [ list access-list-name ] [ asn as-access-list-number ] [ route-map map-name ]
http://www.cisco.com/en/US/docs/ios-xml/ios/ipmulti/command/imc_i2.html#wp2930691609
Hope to help
Giuseppe
04-22-2013 01:11 PM
Hello Giuseppe, I dont quite understand MSDP in this context - I am very new to multicast. Does this mean I have MSDP peerings with each and every single one of my WAN routers (ASRs). What will the filters be helping me achieve?
In my case I can afford to use different multicast addresses at each site...
I had a go with a multicast lab with a basic setup:
All routers have converged through OSPF, each link is a point-to-point link.
I have created MSDP peering with ETASR01 and 02 sharing the 20.1.1.1 RP address (anycast)
And have allowed that RP address to be the RP for the multicast group 224.1.1.1
Also the same with SQPASR01 and 02, with 10.1.1.1 RP address only allowed for 234.1.1.1
Just an example config I have done:
hostname ETASR01
!
ip multicast-routing
!
interface Loopback0
ip address 20.1.1.1 255.255.255.255
ip ospf network point-to-point
ip ospf 1 area 0
!
interface Loopback1
ip address 20.0.0.1 255.255.255.255
ip ospf network point-to-point
ip ospf 1 area 0
!
interface FastEthernet0/0
ip address 192.168.20.1 255.255.255.252
ip pim sparse-mode
ip ospf network point-to-point
ip ospf 1 area 0
!
interface FastEthernet0/1
ip address 192.168.21.1 255.255.255.252
ip pim sparse-mode
ip ospf network point-to-point
ip ospf 1 area 0
!
interface FastEthernet1/0
no switchport
ip address 192.168.1.2 255.255.255.252
ip pim sparse-mode
ip ospf network point-to-point
ip ospf 1 area 0
!
router ospf 1
log-adjacency-changes
!
ip pim rp-address 10.1.1.1 IPTV
ip pim rp-address 20.1.1.1 Altiris
ip msdp peer 20.0.0.2 connect-source Loopback1
ip msdp originator-id Loopback1
!
ip access-list standard Altiris
permit 224.1.1.1
ip access-list standard IPTV
permit 234.1.1.1
!
This provides me with my anycast - redundancy
And also provides me with control on which RP is taking care of multicast groups. Does this look right?
I tested with an 'ip igmp join-group 234.1.1.1' on IPTV and did a ping from Altiris to the address of 234.1.1.1 and I did get a response back from the interface which shows that it is working.
Thank you for your help.
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01-02-2018 03:32 AM
can I use the same multicast group addresses for the IPTV channels in the two sites ?
01-02-2018 04:45 AM
01-02-2018 05:08 AM
So if i will make msdp betwern two sites and also anycast (the same rp betwern two sites) can i use the same multicast group addresses for the channels and the reciever in each site will reach to the source (channel multicast group address) which closed to the rp( shortest path) correct?
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