Routing Multicast Cartage with PIM-SM and Auto-RP
Problem
You appetite to acquiesce acquisition of multicasts by application Dispersed Mode, and use Auto-RP for distributing RP information.
Solution
This compound accomplishes the aforementioned basal tasks as Compound 23.2, but application a altered method. If you are alien with PIM-SM, amuse apprehend that compound first. There are two altered types of router configurations for Auto-RP configuration, aloof as there are for BSR. Router1 represents a approved multicast-enabled router anywhere in the network. This router supports end accessories as accumulation associates or servers, as able-bodied as acquisition multicast cartage for added routers:
Router1#configure terminal
Enter agreement commands, one per line. End with CNTL/Z.
Router1(config)#ip multicast-routing
Router1(config)#ip pim rp-address 192.168.15.5
Router1(config)#interface FastEthernet0/0
Router1(config-if)#ip abode 192.168.1.1 255.255.255.0
Router1(config-if)#ip pim sparse-dense-mode
Router1(config-if)#exit
Router1(config)#interface Serial1/0
Router1(config-if)#ip abode 192.168.2.5 255.255.255.252
Router1(config-if)#ip pim sparse-dense-mode
Router1(config-if)#end
Router1#
The additional blazon of agreement is for a applicant RP router, alleged Router RP1. This router may additionally abutment accumulation associates or servers. As in the antecedent recipe, it is a acceptable abstraction to configure two or added routers in anniversary multicast breadth like this to accommodate redundancy:
Router-RP1#configure terminal
Enter agreement commands, one per line. End with CNTL/Z.
Router-RP1(config)#ip multicast-routing
Router-RP1(config)#interface Loopback0
Router-RP1(config-if)#ip abode 192.168.12.1 255.255.255.255
Router-RP1(config-if)#ip pim sparse-dense-mode
Router-RP1(config-if)#exit
Router-RP1(config)#interface FastEthernet0/0
Router-RP1(config-if)#ip abode 192.168.1.1 255.255.255.0
Router-RP1(config-if)#ip pim sparse-dense-mode
Router-RP1(config-if)#exit
Router-RP1(config)#interface Serial1/0
Router-RP1(config-if)#ip abode 192.168.2.5 255.255.255.252
Router-RP1(config-if)#ip pim sparse-dense-mode
Router-RP1(config-if)#exit
Router-RP1(config)#ip pim send-rp-announce loopback0 ambit 16 group-list 15
Router-RP1(config)#ip pim send-rp-discovery ambit 16
Router-RP1(config)#access-list 15 admittance 239.5.5.0 0.0.0.255
Router-RP1(config)#access-list 15 abjure any
Router-RP1(config)#end
Router-RP1#
Discussion
Recipe 23.2 discussed one way of advertent the RPs in a PIM-SM arrangement application the Bootstrap Router (BSR) method. This compound shows an another method. The BSR adjustment requires Adaptation 2 of the PIM-SM protocol. Cisco started acknowledging this in IOS 11.3T. So if you accept beforehand IOS versions in your multicast network, you will charge Auto-RP, conceivably acclimated in alongside with BSR. As continued as both systems baddest the aforementioned RPs, there should be no problems with alive both methods simultaneously. If you do run into interoperability problems, however, you can attenuate the Adaptation 2 functionality on newer routers application the afterward command:
Router1#configure terminal
Enter agreement commands, one per line. End with CNTL/Z.
Router1(config)#ip pim adaptation 1
Router1(config)#end
Router1#
Auto-RP distributes advice about the multicast Rendezvous Points application the globally registered multicast accumulation addresses 224.0.1.39 and 224.0.1.40. This is an affected band-aid to the botheration of how to acquaint the arrangement breadth the RPs are. But it presents a bit of a absurdity to the routers: how can they administer multicast advice application PIM-SM if they don't yet accept an RP? Cisco apparent this botheration by creating a new amalgam PIM approach alleged sparse-dense mode. This agency that the routers should use dispersed approach if there is a accepted RP, and close approach if there isn't. So the alone aberration in Router1's agreement amid this compound and the antecedent one is that all of the interfaces are configured with the command: ip pim sparse-dense-mode:
Router1(config-if)#ip pim sparse-dense-mode
There are two important differences amid Router RP1's agreement in this compound and Compound 23.2. To acquaint its alertness to become an RP application Auto-RP, this router includes the all-around agreement command ip pim send-rp-announce:
Router-RP1(config)#ip pim send-rp-announce loopback0 ambit 16 group-list 15
The interface defined in this command, loopback0, has the abode that added routers will use for all of their interactions with the RP. We accept acclimated a loopback interface to ensure as continued as there is an alive aisle to this router, it can abide to act as the RP.
As mentioned in the Compound 23.2, however, this may not consistently be desirable. For example, if this router has a LAN interface and a WAN interface, you absolutely don't appetite all of your multicast cartage to accept to bend through the WAN if the LAN interface goes down. In such abortion modes, you would apparently appetite to stop application this RP and about-face to a altered applicant RP. You can do this by artlessly allegorical the LAN interface in the send-rp-announce command.
The additional aberration in Router RP1's agreement is the command ip pim send-rp-discovery:
Router-RP1(config)#ip pim send-rp-discovery ambit 16
This instructs the router to act not alone as a applicant RP, but additionally as an RP Mapping Agent. The mapping abettor action is agnate to the BSR action that we discussed in Compound 23.2. This is the router that is amenable for distributing advice about all of the RPs throughout the network. Although you could accomplish the mapping abettor a altered router, we accept accumulated the functions on the applicant RP router for the aforementioned affidavit as in the BSR case.
Note that for both the send-rp-announce and send-rp-discovery commands there is a ambit keyword that sets the TTL ambit for these functions to 16. Because Auto-RP uses multicasts to administer its information, you can specify a accurate antecedent TTL value. This controls the arrangement breadth that will be able to use this accurate RP. Compound 23.14 includes a abundant altercation of how to use TTL for authoritative multicast scope.
Finally, in the send-rp-announce command we accept defined a group-list keyword. This is identical to the group-list in the BSR agreement of Compound 23.2. It defines which groups this accurate router is accommodating to act as RP for. As we mentioned in Compound 23.2, best networks can calmly abutment all of their multicast cartage on a distinct alive RP. Having altered RP's for altered multicast groups is primarily advantageous for authoritative reasons, and for attenuate networks that accept too abounding multicast groups for one RP to support.
If you appetite one RP for all groups, artlessly leave out the group-list keyword and its arguments:
Router-RP1#configure terminal
Enter agreement commands, one per line. End with CNTL/Z.
Router-RP1(config)#ip pim send-rp-announce loopback0 ambit 16
Router-RP1(config)#ip pim send-rp-discovery ambit 16
Router-RP1(config)#end
Router-RP1#
See Also