I am having a strange issue on Remote SPAN. I have Remote SPAN setup across multiple switches and also configured rspan vlan be part of trunk between the switches.
Here is source switch (switch_A):
monitor session 66 source interface Gi1/0/1
monitor session 66 destination remote vlan 999
Here is destination switch (Catalyst 3560 switch_B):
monitor session 66 destination interface Fa0/1
monitor session 66 source remote vlan 999
On the switch_B, the uplink also carries other user vlans. It seems like when I plug-in my wireshark into switch_B fa0/1, the wireshark also pickup IPv6 traffic (MDNS, DHCPv6 Solicit, UDP IPv6 Multicast) from other vlan that is part of switch_B trunk and those IPv6 is not in source switch at all.
I have checked all my switches and only switch_A had source RSPAN at this time. Just wondering is MDNS, DHCPv6 Solicit, IPv6 Multicast can across vlans? Any suggestions are appreciated.