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Question regarding iGMP snooping and VLAN extended mode

Trusted Contributor

Question regarding iGMP snooping and VLAN extended mode

Some VC questions from Andrea:




1. I would ask you if it is possible to enable Vlan extended mode in Version 3.60 online.

The manual tell me if I don’t have 1/10 Gb Modules and my Configuration is running Version 3.30 or above it is possible to change . But is it possible to change this settings online ?


2. The same is for IGMP snooping , could I set this setting online ?

In the Manual is just described , that its available and I could enable this , but nothing else.


3. I did not see anything on the User Guide, so I suppose that old G5/G1 blades will support Extended VLAN capacity if connected to a Flex10/FlexFabric, am I right?




Reply from Markus:




1. Yes, because it doesn’t affect current VLANs that are created. It just lifts the upper limit (>320) on what can be created as long as VC 1/10 & VC 1/10-F are not present or else they will be marked Incompatible.

Modifying it back to Legacy requires a deletion of the domain. No risk here.


2. Yes, but I would clarify what you mean by Online. If you make a change to IGMP Settings on VC, the forwarding of multicast frames is going to behave differently than before you hit apply.

Does this cause things to fail or interrupt? It really depends on what has been done within the networks infrastructure to allow for this because In order for IGMP, and thus IGMP snooping, to function… a multicast router must exist on the network and generate IGMP queries. Potential risk here.




And Dan also replied:




Yes, should work fine.  The setting was based on a limitation in the VCmodules themselves.


Individual blades don't really care as VLAN tags are processed by the OS.


TOE settings might change this answer but you can always turn that off.




Any other input or questions?