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Re: pim routing with v1910 switches?

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pim routing with v1910 switches?



I am attempting to understand pim routing with the v1910 switches, and how to fit it in to a desired configuration.



The userguide states simply:


"An IGMP snooping enabled switch deems that all its ports on which IGMP general queries wth the source address other than or PIM hello messages are received to be router ports."  That's fine.



An additional pim router that I have interconnected registers for a multicast group as a router (being listed in the IGMP snooping gui) only when the switch gains knowledge of the multicast group through a membership query response IGMP packet.  I have configured the v1910 to "Drop Unknown".  This is fine, except the following very odd activity is occuring:


1) the multicast group is unknown to the v1910, so far as it is not listed/learned by the switch's igmp snooper.

2) I send traffic to this multicast group.

3) The configured pim router receives all of the multicast packets (the pim router interconnected to the switch).


This seems extremely odd to me, particularly because I have "drop unknown" configured.  Also, it's VERY important to note that no additional nodes recieve the multicast packets.


Here is a second condition that tends to make more sense:

1) a client on the v1910 JOINs the multicast group.

2) the multicast group is then KNOWN to the v1910, so far as it is listed/learned by the switch's igmp snooper.

3) I send traffic to this multicast group

4) The configured pim router receives all of the multicast packets AND it is registered as a router for the multicast group (in fact ALL multicast groups for which the v1910 has learned).



So, under the above, it's clear that the switch is not properly regulating the drop unknown activity, and will send multicast packets to the interconnected pim router at all times.


How do I stop this?


Some concerning things are:

1) the interconnected pim router has an igmp querier.

2) the interconnected pim router has a pim table present.


Do they not support pim sparse mode?



These switches don't appear to be high end, but it's quite clear they are capable of handling pim router (it appears that they might not like sparse mode, but it's unclear); so I'd expect that they act normal in respects to pim.



Any assistance is appreciated.








P.S. this thread has been moevd from LAN Routing to Web and Unmanaged. - Hp forum moderator

Trusted Contributor

Re: pim routing with v1910 switches?

Just some thoughts


- If you want to block certain multicast, use ACLs, look for "igmp group-policy acl-number"


- Well, V1910 support IPv4/IPv6 unicast routing and IGMVP v1/v2/v3 and works very well with PIM-SM enabled routers on the uplink.


Re: pim routing with v1910 switches?

Thanks for the reply.



I think you mean to say it doesn't support sparse mode, but does support dense?


I say this because it appears that the v1910 with igmp snooping+a querier enabled can "automatically detect" a neighboring v1910 with igmp snooping+a querier enabled.  In this instance, there are two interconnected on ports configured to be on the same (VLAN90).


I can have a single switch's VLAN interface (VLAN90) configured to be a querier and snooping enabled on both switches, and the table is built.


An example of a multicast group's entry is in the attached screenshot.


The UI reports that the interconnected switch is a (multicast) router.  From what I can see... if I configure an additional pim router (in sparse mode particularly), the previously describe oddity happens.  I'm just confused whether it's truly an oddity or if I'm just misunderstanding what's going on.



My goal is to route multicast through two separate interfaces on a firewall (where policies exist), so configuring pim routing is a necessity.


I've attached a diagram of what I desire to be the configuration when I am done.  I have a third router involved, so I'm trying to fully understand what's going on before I bother integrating it.


It seems like a very trivial design, so I'm really surprised that I can't find much info anywhere on how to do it properly.



Thanks very much!






After opening a ticket with HP support, I was able to prove that PIM is not supported on the switches.  However, IGMP snooping clearly is (as the respondant above originally stated before removing the sentence, due to them believing my arrogance).


The final conclusion was that I can not stop packets from arriving to the interfaces as I wish.  I will instead implement tighter controls on my firewall policy only allowing specific groups.