06-06-2014 02:42 AM - edited 03-07-2019 07:39 PM
Hello
I am experiencing a strange problem and would be grateful to have some advice on this.
I have a Switch (WS-C3750X-48P-S) version (flash:/c3750e-universalk9-mz.122-55.SE5).
I have two devices connected on two ports of the switch Gi1/0/41 and Gi1/0/42.
The configuration on the interfaces are as follows:
interface GigabitEthernet1/0/41
description ### ALert Logic monitor port ###
switchport access vlan 2
switchport mode access
load-interval 30
duplex full
spanning-tree portfast
end
sw01#sh run int Gi1/0/42
Building configuration...
Current configuration : 196 bytes
!
interface GigabitEthernet1/0/42
description ### ALert Logic monitor port ###
switchport access vlan 2
switchport mode access
load-interval 30
duplex full
spanning-tree portfast
end
But I cannot see them on the MAC address table
sw01#sh mac address-table int Gi1/0/41
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
sw01#sh mac address-table int Gi1/0/42
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
I was able to see that a couple of hours back
sh mac address-table int Gi1/0/41
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
2 a036.9f36.d885 DYNAMIC Gi1/0/41
Total Mac Addresses for this criterion: 1
sw01# sh mac address-table int Gi1/0/42
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
2 a036.9f36.d884 DYNAMIC Gi1/0/42
Total Mac Addresses for this criterion: 1
But since I could not see IP addresses getting associated to the MAC addresses, I did a shut / no shut on the port but have not been able to see the MAC address since. Any advice as to what may have gone wrong?
sw01(config)#int Gi1/0/41
sw01(config-if)#no shut
sw01(config-if)#int Gi1/0/42
sw01(config-if)#no shut
sw01(config-if)#^Z
Any hints would be much appreciated.
Thanks
Kaushik
06-06-2014 05:31 AM
Sorry but anyone seen this problem before?
06-06-2014 12:45 PM
Hey,
it can happen with NIC teaming, as William said check the virtual mac associated, also the keep-alive intervals under the NIC teaming options.
Regards,
RS
06-07-2014 09:50 AM
Is it the switch where the node is directly connected ?
Is the NIC at node side, working fine ?
Another fact to consider is, a mac will wipe itself out after the MAC-age timeout.
--
Parvesh
06-07-2014 02:16 PM
are those devices are working or idle.may be the mac address table got cleared/expired and there is no traffic initiated or destined to those devices after that.
Regards
Prajith
06-06-2014 07:17 AM
Are the interfaces currently showing up/up?
06-06-2014 07:24 AM
Yes, I think I may have found the problem.
I think someone connected two NICs of the same device to the same Switch and VLAN. I think that may be causing this issue?
06-06-2014 07:32 AM
If they're using NIC teaming, a virtual MAC may have been assigned to the pair of NICs. You'd need to get a list of any real and virtual MACs from the server admins to nail down the connections.
06-06-2014 08:13 AM
Are those devices up and their NIC's are not in power save mode?
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