cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Announcements

CISCO SWITCHES FOR SMALL and MEDIUM BUSINESS

Introducing the next generation of Cisco Small and Medium Business Switches. Cisco is refreshing its SMB Switch portfolio. Click here  to learn more.


668
Views
0
Helpful
3
Replies
Highlighted
Beginner

SG300-28P identifies itself as a duplicate IGMP Querier IP address

25-Jun-2015 08:44:45 %BRG_IGMP_QRR-W-DUPLICATE_IP: Duplicate IGMP Querier IP address 192.168.142.1 detected on VLAN 1. Remote MAC address is 34:a8:4e:0d:34:55.

 

I am seeing this regularly on this SG300-28P switch.  These IP and MAC addresses belongs to the switch itself and it is the IGMP querier.  I don't understand why the switch is identifying itself as a duplicate - has it got split personality disorder??  Have I messed up on the configuration somewhere?

Everyone's tags (2)
3 REPLIES 3
Advocate

Is IGMP snooping enabled or a

Is IGMP snooping enabled or a mrouter defined? Sounds you're getting duplicate reports.

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
Beginner

Yes, IGMP snooping is enabled

Yes, IGMP snooping is enabled on this switch and it's is the querier.

I've used the following configuration:

ip igmp snooping
ip igmp snooping vlan 1
ip igmp snooping vlan 1 querier

Beginner

There's no mrouter defined,

There's no mrouter defined, but according to the CLI guide, by default "Learning pim-dvmrp is enabled."

Before I configured IGMP snooping, I used Wireshark to determine that multicast packets were being flooded to all ports on each switch, which was the reason for configuring IGMP snooping in the first place.

Bonjour is also enabled on the switch, but I've never really understood what it does - I just know it's enabled by default.

bonjour interface range vlan 1

I tried moving the IGMP snooping to another switch, but I get the same message there too.  Definitely no duplicate IP addresses on the network, which was what I thought the message was telling me at first.