Ethernet Error Speed 10 or 100 Mbps, Half or Full Duplex....Very confusing..

[Anonymous]

Hi, I'm seeing these errors under 7100, Utilities, Troubleshooting, Physical Interface.  It seems like the only way I can get the error to go away is set the Adtran Interface to Ethernet 10M/Half Duplex.  It does not make sense.  Can someone shed some light into it?  Is the Adtran Switch not auto negotiating.  I've look at the Polycom Phone Specs, it is 100M Full Duplex.

There is a speed/duplex mismatch on port eth 0/14 with Polycom SoundPoint IP 335.   Local: 100M Full Duplex   Neighbor: 10M Full Duplex

There is a speed/duplex mismatch on port eth 0/14 with Polycom SoundPoint IP 335.   Local: 100M Full Duplex   Neighbor: 10M Full Duplex

There is a speed/duplex mismatch on port eth 0/16 with Polycom SoundPoint IP 335.   Local: 100M Full Duplex   Neighbor: 10M Full Duplex

There is a speed/duplex mismatch on port eth 0/16 with Polycom SoundPoint IP 335.   Local: 100M Full Duplex   Neighbor: 10M Full Duplex

[Anonymous]

The default action for any AOS switch device is to auto-negotiate speed and duplex settings. Polycom phones should do the same. If you set the speed to auto in the 7100, does a "show int eth 0/X" (where X is the switchport in question) show the interface as full duplex?

[Anonymous · Accepted solution]

I got an answer from Tech Support yesterday.  The firmware version on Polycom Phone IP 335 have a known bugs.  If I turn off LLDP all the errors goes away.  I guess Polycom Phone was broadcasting they are 10Mbps/Half Duplex instead of 100Mbps/Full Duplex.

[Anonymous]

As an update, in R10.11.0 AOS, a switchport command was added that allows an AOS switch the ability to ignore these LLDP speed-duplex mismatch messages.  If you add the command "no lldp receive 802.3-info mac-phy-config" to any applicable switchports, the switch will no longer log every LLDP update indicating a mismatch as an event in the event-history.