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ziffusion · 07-03-2018

I have a SPAN monitor session setup to capture both tx/rx on a port 9 (see below). And I can see the multicast count ticking up on port 9. But none of the multicast packets show up in the SPAN session (and they don't seem to be making it across the s...

ziffusion · 06-30-2018

Is the Catalyst 2960 switch capable of generating logs about how it handles traffic on a port (why it drops it, for example)? How can I turn this on?

ziffusion · 07-09-2018

Thanks for looking this up. Turned out to be a stupid problem. There was a VLAN header on the frames that was causing the switch to drop them. SPAN wouldn't show these frames to me (don't know why), but counted them in the stats. Wireshark wouldn't...

ziffusion · 07-03-2018

@chrihussey Yes, the device is on port 9, and the SPAN destination is port 10 (where I am sniffing the traffic). The eventual destination for the multicast traffic is elsewhere, across a couple of routers. I can see IGMPv3 and unicast in the SPAN j...

ziffusion · 07-03-2018

Yes, I disabled it because I wanted to eliminate that as the problem. But the behavior is the same in either case. With IGMP snooping turned off, the switch ought to be flooding multicast to all ports, without looking for a listener.

ziffusion · 07-03-2018

@chrihussey SwitchB#sh ip igmp snooping detail Global IGMP Snooping configuration: ------------------------------------------- IGMP snooping : Disabled IGMPv3 snooping : Disabled Report suppression : Disabled...

ziffusion · 07-03-2018

Here is the output of "show interface <port> control". Doesn't look like it's dropping traffic.But the multicast frames don't show up in the SPAN session, and don't seem to be switched.The multicast number does keep going up, so it's counting somet...

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Multicast frames are not showing in the SPAN session (on Catalyst 2960)

How can I debug why the Catalyst 2960 is dropping traffic?

Re: Multicast frames are not showing in the SPAN session (on Catalyst 2960)

Re: Multicast frames are not showing in the SPAN session (on Catalyst 2960)

Re: Multicast frames are not showing in the SPAN session (on Catalyst 2960)

Re: Multicast frames are not showing in the SPAN session (on Catalyst 2960)

Re: How can I debug why the Catalyst 2960 is dropping traffic?