Hi all,
I've been troubleshooting this issue for last week, we have 5x WS-C3750-48P switches in a stack with
Cisco IOS Software, C3750 Software (C3750-IPBASEK9-M), Version 12.2(52)SE
and 7941 IP Phones with Firwamware: TERM41.7-0-3-0S
Have tried following firmware as well, with same result: SCCP41.8-4-3S
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Switchport configuration:
interface FastEthernet5/0/22
description DESKTOP & VOIP PORT
switchport access vlan 303
switchport mode access
switchport voice vlan 4
switchport port-security
switchport port-security maximum 2
switchport port-security aging time 5
switchport port-security violation protect
ip access-group 100 in
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
mls qos trust device cisco-phone
mls qos trust cos
auto qos voip cisco-phone
no mdix auto
storm-control broadcast level 1.00
storm-control multicast level 1.00
storm-control action shutdown
spanning-tree portfast
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Problem description:
For some reason, once in a while the switch sees the MAC address of the phone in both VLAN's, data and voice.
like this:
MOR-SBE-ASW03#show port-security interface f5/0/22 address
Secure Mac Address Table
------------------------------------------------------------------------
Vlan Mac Address Type Ports Remaining Age
(mins)
---- ----------- ---- ----- -------------
303 001e.135c.efe4 SecureDynamic Fa5/0/22 5
303 0026.b9ce.a499 SecureDynamic Fa5/0/22 5
------------------------------------------------------------------------
Total Addresses: 2
And therefore the phone can't communicate with the CallManager, therefore trying to re-register.
But it can't re-register until the Aging time on the switchport ages out the MAC on vlan 303 (data), and if we're lucky then it learns it on VLAN 4 just in time to register the phone.
I can't reproduce the problem. It happens quite a few times per day.
It does not happen to all the phones on this switch. Only to some of them.
Have done following troubleshooting steps:
1) If I remove port-security it works fine.
2) If I put port-security violation mode shutdown/restrict, it works fine too. It seems to happen with only protect mode.
3) It does not happen to all phones.
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I do not understand why the switch learns the phone's MAC in a Data VLAN 303. It should appear only in voice vlan.
Will appreciate any help,
Thanks,
George
