Inter-AS multicastVPN

[devang_etcom]

Does pim Sparse-mode support the inter-as multicast VPN?

i guess only PIM SSM supports the multicast vpn in inter-as configuration... just to cross check...

regards

Devang Patel

[Harold Ritter]

Devang,

It is certainly possible to support PIM Sparse mode ASM in an InterAS context. You would simply need to use MSDP between the two ASes. SSM would definitely be simpler though. SSM does require that all routers support the mBGP MDT SAFI.

Regards,

[shivlu jain]

MDT safi is only required on sender side , receiver can be used any.

regards

shivlu

[Harold Ritter]

Shivlu,

The PEs are both senders and receivers as far as the default MDT is concerned.

Regards,

[shivlu jain]

Hritter

You are right but I am talking about mdt-safi not mdt-default, have tested in my LAB in which my source is using mdt-safi and receiver is using only MP-BGP with default mdt.

regards

shivlu

[Harold Ritter]

Shivlu,

The MDT SAFI is used by a PE to signal itself as a new source on the default MDT to the other PEs.

Therefore you would need to have MDT SAFI support on both sides.

Regards,

[shivlu jain]

hritter

Thanks

regards

shivlu

[chintan-shah]

Hi Hritter,

We use MSDP between two ASes in case we run PIM-SM in our core. Usually we run MSDP in our network on Core router -may be few Tier1 sites.. Now in case I need to run MSDP to other AS , Shall I use diff router which gets all SA from Core MSDP and then pass to diff AS ?? What is best practice ?

We might think of Option B as Inter-AS for mVPN as we already run Option B for normal L3 VPN with out partnet service provider....

Rgards,

Chintan

[shivlu jain]

chintan

remember one thing it should not be extranet. Because anycast is not going to work with extranet.

SSM is the only supported for inter-as communication.

regards

shivlu jain

[Harold Ritter]

Shivlu,

Are you referring to Extranet or InterAS?

I am not sure what you mean by "SSM is the only supported for inter-as communication".

You could certainly have ASM to work with InterAS mVPN by having one RP in each AS exchanging Source Active (SA) messages between themselves. This would be in a option 10c context though.

Regards

[chintan-shah]

Hi Hritter,

I was going through below link for inter-AS :

http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/iasmcvpn.html

I see that option C also cisco indicates to use PIM-SSM , BGP MDT SAFI. In fact, cisco says that PIM-SSM in core is must for even default MDT for otpoin B & C.

Is it true that i can't have option C if i have PIM-SM (ASM) in core for default MDT ? I can't find any example on CCO.

Regards,

Chintan

[Harold Ritter]

Chintan,

You can definitely use ASM with option C. In fact, this is the only way you would be able to interoperate with the other vendor.

The idea, would be to have an RP (or group of RPs) in each AS and to run MSDP between the RPs in each AS.

Regards

[shivlu jain]

hritter

The document posted by chintan is also saying that SSM should be in the core in case of inter-as mvpn. May be the document is old but I donot think so for mVPN still cisco supports anycast. Anycast with msdp is for ip vpn inter as cloud. Kindly clarify can we use anycast for mVPN if yes please provide the doc link.

To all:- One thing i would like to add if you are going for mVPN with SSM in inter-as then mdt safi should be used because in previous implementation of cisco type 2 rd is used which is actually for inter-as communication.

regards

shivlu jain

[Harold Ritter]

Shivlu,

I am not referring to Anycast here but rather to running ASM (pim-sm) with a separate RP per AS and then an MSDP session between the two ASes so that PEs in one AS can join the source tree to a PE in the other AS. Again, this would be your only option if you were to build an InterAS mVPN network in a dual vendor environment.

Regards

[chintan-shah]

Hi Hritter,

So, as you said I use ASM(PIM-SM) in my core for Default MDT with multivendor enviroment and also do Inter-AS with partner using MSDP between our AS RP and partnet RP. Thanks for clarification on this .

But at the same time i will still require to use RFP Vector, BGP connector attribute for option C for RPF check on remote AS P router?? and i guess that is too also only supported in cisco so can i still go ahead with multivendor enviroment ??

I would apprcieate if you can share some case study , document for Inter-AS when i have ASM in Core and use MSDP between two AS.

Thanks again,

Regards,

Chintan