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New Member

IPv6 ND through 3560G

Hi all,
we are currently trying to establish IPv6 between two routers. The routers
are connected to 3560G switches (c3560-ipbasek9-mz.122-58.SE2).
We have some issues with IPv6 neighbor discovery, the routers did not see
each other in neighbor table (IPv4 ARP works fine). After connecting them
to 3750 switches everything works fine so the issue is most likely related to
the 3560G switches.
All switches act as L2 devices, no routing between the routers interfaces.
Though it should only be related to L3 functions of the 3560G "sdm pre
dual-ipv4-and-ipv6" might be a solution, also a newer IOS could also be an
option, but as the switches are in a productive state, a reload is not
possible without a lot of paper work.
Any other ideas would be appreciated ;-)

Thanks and best regards,

  • IPv6 Integration and Transition
Everyone's tags (1)

Hi Mario,Do you have MLD

Hi Mario,

Do you have MLD snooping enabled on the switch?

Try : no ipv6 mld snooping


If you run tcpdump on one of the servers do you see the other servers NS packets reaching it interface?


I have encoutered a string of problems with IPv6 ND/ RA on 3750 platform, your issue may be related:






New Member

Hi Seb,

Hi Seb,


the 3560G does not support any IPv6 commands right now. It might support IPv6 L3 commands after setting the SDM template to

sdm prefer dual-ipv4-and-ipv6

We thought that they just switch the IPv6 packets between the routers, so it must not be aware of the IP protocol version. I think it's a bug in 12.2-58 IOS. I think we will plug the routers into the 3750 switches to solve the issue.

BTW: I have no access to the routers, only to the policies...