[Xorp-users] ASM Configuration Options with XORP

[Archimedes S. Gaviola]

Pavlin Radoslavov wrote:
> Archimedes S. Gaviola <agaviola at infoweapons.com> wrote:
>
>   
>> To Whom It May Concerned:
>>
>> Hello and good day! I have 2 multicast routers running XORP 1.4 and I 
>> want to configure it with ASM. I have tried SSM which is more 
>> straightforward to configure because only few configurations options 
>> were being set in the configuration file (config.boot). In the manual, I 
>> could see the options like
>>
>> static-rps
>> bootstrap (with sub options of candidate BSR and candidate RP)
>>
>> In my scenario were there are 2 ASM multicast routers, I am going to 
>> have the same RP address in the static-rps option? When I am going to 
>>     
>
> Yes, if you decide that you are going to use static RPs in your
> network, then all PIM-SM routers must have exactly same set of
> static RPs configuration.
>
>   
>> use bootstrap option? Is it used to configure both the multicast 
>> routers? What about candidate BSR and candidate RP, when to use them? My 
>> goal is to setup a very simple ASM network with a streaming server on 
>> one side of the network behind a multicast router and streaming clients 
>> on the other side with another multicast router.
>>     
>
> If you have a very small number of PIM-SM routers, then static RPs
> is a simpler mechanism: simpler to understand, configure and debug.
> The downside is that it is static and error-prone.
> If you decide to change the Cand-RP set then you need to reconfigure
> all of your routers. The reconfiguration should happen while there
> is no multicast streaming otherwise you might create a multicast
> loop and bring the whole network down.
> Another downside is that if you have redundant links and the current
> RP (as defined in the static config) is disconnected, the rest of
> the network won't be able to use multicast.
>
> The Bootstrap mechanism is dynamic and doesn't have the
> disadvantages listed above. However, it is more complex to
> understand and is more difficult to debug.
>
> It looks like you have a very simple topology: just two multicast
> routers with a single link between them.
> In that case I think a single static RP should be fine. For
> efficiency (to avoid the PIM Register encapsulation) you might want
> to select the RP to be the router that is directly connected to the
> sender.
> Just don't forget to have same state-rps statement in both routers :)
>
> Pavlin
>
>   
Thanks Pavlin for a wonderful explanation! For now this is just a simple 
multicast topology but I may reconfigure my routers soon when needed for 
more additional multicast routers. I can now proceed with my ASM 
configuration.