topic Drop Rx Issues on Edge in Switches, Hubs, and Modems

Drop Rx Issues on Edge

CDTi — Thu, 22 Nov 2007 03:36:09 GMT

I am experiencing massive drops rx on the edge switches and struggling to find this issue? If I sho interfaces on the edge I am getting roughly 10 errors every 5 mins minimum. After an hour this suddenley jumps to 151,341,520 and keeps counting up.

We are experiencing picture breakup on the IPTV at the same time.

If I look on the Core switches the errors are not being shown on the uplink on that side.

Edge Switches are H10.37 firmware and 2626-PWR and Core switches are 5406zl's.

All are uplinked by primary and a diverse fibre using J4858 SX GBIC's. Maximum fibre route is 350m so the SX GBIC's are within specification.

My only query is that I have all uplink ports set to Auto as HP training textbook. Should I force these to 1000-full on both sides?

Any further suggestions for fault finding would be appreciated.

Thanks.

Re: Drop Rx Issues on Edge

Roar Pettersen_1 — Thu, 22 Nov 2007 05:39:58 GMT

Hi !

Make sure that you are using latest and newest firmware on both swithes H.10.50 and
K.12.51.

If this doen't help, then it is time to clean the fiber patch cables and fiber connectors.

Re: Drop Rx Issues on Edge

Matt Hobbs — Thu, 22 Nov 2007 07:28:54 GMT

Is this IPTV multicast based? If so, are the multicast sources connected to the 5300's and do they have IGMP enabled?

Drops RX are more an indication of an inbound buffering problem.

Re: Drop Rx Issues on Edge

CDTi — Thu, 22 Nov 2007 07:39:23 GMT

Hi,

Firmware installed is 3 months old worst and be surprised if this is the issue. I have 54 Edge and 2 Cores to do so I would prefer not to have to do this if required....

The entire IPTV system is multicast based.

IGMP is enabled on the system as well as PIM-SM mode. I have also enabled source-port-filtering on the 2626-PWR switches to the uplinks as well as IGMP Delayed Flush set at 100.

Can you expand on the inbound buffering problem if possible Matt and advise how to fault check this?

Many thanks.

Re: Drop Rx Issues on Edge

Matt Hobbs — Thu, 22 Nov 2007 15:50:13 GMT

Buffering could come into play if there was simply more traffic on ports 1-24 (i.e up to 2.4Gbit) than what could be transmitted out port 25/26 at any given time.

It's probably unlikely though as most of these cameras will at maximum send at around 10Mbit each. Please correct me if I'm wrong.

Is it only ports 1-24 that are seeing these drops? The uplinks and the core switches are okay?

How stable is the spanning-tree topology? How many topology changes have there been and when was the last? "show span".

If the spanning-tree is blocking the uplink port now and then, then possibly there is a backlog of frames that cannot be transmitted during this time which therefore get dropped.

Re: Drop Rx Issues on Edge

Case Van Horsen — Tue, 27 Nov 2007 12:58:34 GMT

This may be a stretch, but do you have broadcast-limit enabled? If so, try removing it.

I've found broadcast-limit to trigger more often that I had expected. The dropped broadcast would increment dropped packet counters.

casevh