error in 4948 switch

wajid dabir · ‎03-13-2013

My cisco 4948 switch is generating the below error,how do i troubleshoot this error.

*Mar 13 00:09:33.451: %C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: (Suppressed 14 times)Packet received with invalid source MAC addre
ss (00:00:00:00:00:00) on port Gi1/37 in vlan 1

Gi1/37- to this port another 2950 switch is conneted by trunk link.and to this switch end host is connected i.e.thin client

InayathUlla Sharieff · ‎03-14-2013

Hi Wajid,

%C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: error message.

The default form of error message is:

%C4K_L2MAN-6-INVALIDSOURCEADDRESSPACKET: Packet received with invalid source

MAC address ([mac-addr] ) on port [char] in vlan [dec]

This means a packet was received with an all zero (00:00:00:00:00:00) or a

multicast source address, for example, FF:FF:FF:FF:FF:FF. which is a Layer 2

broadcast. The packet is treated as invalid and no learning is done.

Excessive flow of such packets can waste CPU cycles. This message is

rate-limited and is displayed only for the first such packet received on any

interface or VLAN. Subsequent messages display the cumulative count of all

such packets received in given interval on all interfaces.

Resolution

Check the switch configuration file in order to find the source of these packets on the

specified port and take corrective action in order to fix them at the source end. For

example, it can be due to a faulty NIC or connected hub. You can also setup a SPAN session

to identify the source.

Alternatively, you can also issue the switchport port-security limit rate

invalid-source-mac command in order to enable port security on that interface in order to

shutdown the port if the incoming rate of packets with invalid source mac address is too

high.

HTH

Regards

Inayath

*Plz rate the usefull posts.

wajid dabir · ‎03-17-2013

Dear Inayath,

This error is generating from the 2950 switch,on which port-security limit rate command dont support.i can not apply this command on 4948 port as it will shutdown uplink and all user of 2950 will disconnected.

what config should i do on 2950 switch for port-security.

InayathUlla Sharieff · ‎03-17-2013

Hi Wajid,

Plesae find below link for port-security config for 2950.

http://www.cisco.com/en/US/docs/switches/lan/catalyst2950/software/release/12.1_6_ea2c/configuration/guide/swgports.html#wp1043892

Regards

Inayath