[c-nsp] RP Migration option

[Андрей Андреев]

Thank you.
All your ideas are very helpful to me, I also think about multiple 
Anycast RP in domain.

After reading several materials i see the following migration steps

1) start to use BSR to announce partner RP, so all network devices 
without *override* keyword will use dynamic mapping.
2) then use bsr-border command at ASBR and start to use own network RP 
address.

One problem still exist, partner cant run BSR with us (only MSDP and 
MBGP), so i need to inject partner RP address via BSR in my domain.
If i can do this all PIM speakers in my domain will see BSR RP-Mapping 
without run BSR between domain.

Please review the following algorithm to spoof BSR announce:
1) Put current partner RP address on Loopback as /32 in stub router 
without multicast clients and transit multicast capability.
2) Activate PIM-SM on this interface and cBSR/cRP on this router.
3) Did not announce this address in IGP.

If i right, all my network will see dynamic mapping know by spoof BSR 
and will use external path to partner RP address known by MBGP.

Then i will careful migrate own network and clients to dynamic mappings use.
And finally turn ON own Anycast RPs and turn OFF spoof cBSR/cRP.

Is this right way?




24.02.2012 16:58, Vitkovsky, Adam пишет:
> Hi,
> You mentioned you have a big m-cast network that's why I would recommend using several anycast RPs on routers with close proximity to receivers -this way each RP would serve only a subset of receivers (or two RPs in one locality can split the groups they serve)
>
> In order to achieve this you'd configure the edge(ASBR) as pseudo msdp peer -no RP configured on ASBR (MSDP peers do not have to be an RP to forward SA msgs)
> Than configure msdp peer sessions from the ASBR to all the anycast RPs in your domain
> If you only have receivers in your AS and all sources are in the partner AS -than you can configure your RPs with the default msdp peer to be the ASBR
>
> If you also have sources in your AS you need to make sure the SA msgs get to all other RPs (in both domains) and RPF successfully
> So either use bgp in your AS between all the RPs and the ASBR (no need for msdp full mesh between RPs and ASBR)
> Or you can put all RPs and ASBR into common mesh-group(but that would require a full mesh of msdp peering sessions)
> Though you can avoid the full mesh requirement by putting each ASBR-to-RP session into a different mesh-group -than SA msgs would be passed between the peer-groups on the ASBR (RPF check would be ok)
>
> Now to implement this seamlessly
> By default dynamically learned RP takes precedence over static RP
> Though RP can be configured to take precedence over dynamic/auto RP this requires a lot of configuration on each last hop device
>
> Also note:
> That if you have all the interfaces configured only with: pim sparse mode
> You would need to configure the nodes with: ip pim autorp listener
> -this causes multicast traffic for the two Auto-RP groups(224.0.1.39 and 224.0.1.40) to be PIM dense mode flooded across interfaces operating in PIM sparse mode.
>
> The more convenient migration approach would be to configure the anycast RPs first to support only a dummy m-cast group just to test the solution
> and than to add more and more groups to all anycast RPs to smoothly migrate the particular group to the new Anycast RPs -kind of group by group migration approach
> Unfortunately this can't be scoped by location serviced by particular anycast RP -because as soon as one anycast RP starts acting as auto RP for particular group all the nodes in the network would start to use that RP for this group
>
> Also I'd recommend BSR instead of Auto-RP as BSR can be very nicely scoped at the ASBRs on interfaces to the partner AS with: ip pim bsr border
>
>
> adam
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of ?????? ???????
> Sent: Friday, February 24, 2012 9:33 AM
> To: cisco-nsp at puck.nether.net
> Subject: [c-nsp] RP Migration option
>
> Hi List,
>
> Please advise me how can i use two independent RP at network for same
> groups to smoothly migrate backbone/aggregation devices and client
> equipment to new RP.
>
> We have large network and even more large clients connected via PIM.
> Now all network use static RP address from our partner AS.
> We use PIM to connect to this partner.
>
> Recently we start to use MSDP and MBGP at network edge device.
> We received RP address and multicast source addresses via MBGP for RPF
> check and MSDP also works fine.
>
> I plan to make Anycast RP on this edge device and change RP mapping on
> whole network.
> Is there is any way to do this smoothly?
> I can take window time and change RP at once on my device, but many
> clients cant do this.
> So i need a way to migrate sequentially or partially over the long time.
>
> One good news, Old RP address located beyond the edge router with
> MSDP/MBGP sessions so RPF is completely identical from view of whole
> network.
>
> Backbone and edge run at 7600 - Sup720
> Aggregation ran at 3560/3750
>
> Any opinions and suggestions are welcome.
>
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