N2000 address table count excessive number

Question

While we where deploying network change and moving access ports to another VLAN some ports seems to be stuck after VLAN change. The port status is UP and link auto negotiation is successful, since the host and the switch reports 1000 speed full duplex.#show interfaces configuration gi1/0/10 Port Description Duplex Speed Neg MTU Admin State --------- ------------------------------ ------ ------- ---- ----- ----- Gi1/0/10 xxxxxxxxxx Full 1000 Auto 1518 Upinterface show status:#show interfaces status gi1/0/10 Port Description Duplex Speed Neg Link Flow M VLAN State Ctrl --------- --------------- ------ ------- ---- ------ ----- -- ------------------- Gi1/0/10 xxxxxxxxxx Full 1000 Auto Up Off A 100While the host can see the link is active and is sending packets, the counters on the switch show null.show interfaces counter output:#show interfaces counters gi1/0/10 Port InTotalPkts InUcastPkts InMcastPkts InBcastPkts --------- ---------------- ---------------- ---------------- ---------------- Gi1/0/10 0 0 0 0 Port OutTotalPkts OutUcastPkts OutMcastPkts OutBcastPkts --------- ---------------- ---------------- ---------------- ---------------- Gi1/0/10 3726 0 2839 887 FCS Errors: ................................... 0 Single Collision Frames: ...................... 0 Late Collisions: .............................. 0 Excessive Collisions: ......................... 0 Multiple Collisions: .......................... 0 Received packets dropped  MTU: ............... 0 Transmitted oversized packets: ................ 0 Internal MAC Rx Errors: ....................... 0 Received Pause Frames: ........................ 0 Transmitted Pause Frames: ..................... 0 Receive Packets Discarded: .................... 0 Transmit Packets Discarded: ................... 0 Alternately, from the above output one can tell there are outgoing packets sent from the port but the host reports there is zero packets received.There is not unusual configuration applied to that port:#show running-config interface gi1/0/10 description 'xxxxxxxxxx' spanning-tree portfast spanning-tree portfast bpdufilter default switchport access vlan 100I have found one abnormality, it is dynamic addresses count at the maximum value filling 32 bits:#show mac address-table count interface gi1/0/10 Capacity: 25600 Used: 4294967295 Static addresses: 0 Secure addresses: 0 Dynamic addresses: 4294967295 Internal addresses: 0while there is no addresses assigned to that port:#show mac address-table interface gi1/0/10 Aging time is 300 Sec Vlan Mac Address Type Port -------- --------------------- ----------- --------------------- Forwarding Database Empty. From the second last output is looks like a software bug, the switch cannot register any new MAC address, because Used counter is exceeding Capacity, resulting in dropping incoming packets.This is model N2048 with software version 6.5.3.3, deployed in production as 4 unit stack, and we cannot easily reboot the stack at the moment.Any thought on the above issue? Thanks.

DELL-Josh Cr · Answer

Hi, What happens if you do a shutdown no shutdown on the ports?

sebusel · Answer

Hi Josh,I tried to do that a few times previously and it does not help. Now, I have done it again and I included output from the CLI below:SWITCH#show interfaces status gi1/0/10 Port Description Duplex Speed Neg Link Flow M VLAN State Ctrl --------- --------------- ------ ------- ---- ------ ----- -- ------------------- Gi1/0/10 FAULTY-FREE Full 1000 Auto Up On A 100 SWITCH#show mac address-table interface gigabitethernet 1/0/10 Aging time is 300 Sec Vlan Mac Address Type Port -------- --------------------- ----------- --------------------- Forwarding Database Empty. SWITCH#show mac address-table count interface gigabitethernet 1/0/10 Capacity: 25600 Used: 4294967295 Static addresses: 0 Secure addresses: 0 Dynamic addresses: 4294967295 Internal addresses: 0 SWITCH#show mac address-table count Capacity: 25600 Used: 223 Static addresses: 81 Secure addresses: 0 Dynamic addresses: 140 Internal addresses: 2 SWITCH#conf SWITCH(config)#interface gi1/0/10 SWITCH(config-if-Gi1/0/10)#shutdown SWITCH(config-if-Gi1/0/10)#do show interfaces status gigabitethernet 1/0/10 Port Description Duplex Speed Neg Link Flow M VLAN State Ctrl --------- --------------- ------ ------- ---- ------ ----- -- ------------------- Gi1/0/10 FAULTY-FREE N/A Unknown Auto Down Off A 100 SWITCH(config-if-Gi1/0/10)#no shutdown SWITCH(config-if-Gi1/0/10)#end SWITCH#show mac address-table count interface gigabitethernet 1/0/10 Capacity: 25600 Used: 4294967295 Static addresses: 0 Secure addresses: 0 Dynamic addresses: 4294967295 Internal addresses: 0 SWITCH#show interfaces status gi1/0/10 Port Description Duplex Speed Neg Link Flow M VLAN State Ctrl --------- --------------- ------ ------- ---- ------ ----- -- ------------------- Gi1/0/10 FAULTY-FREE Full 1000 Auto Up Off A 100 Also, I can confirm the same host when connected to another port in the same switch stack sends and receives packets.Thanks,Sebastian

sebusel · Answer

I have done shutdown the port a couple of times, it looks like there is a bug, the dynamic address counter in port Gi1/0/10 stuck at very high value.

Anyone else experienced the same issue?

Thank,

Sebastian

Networking General

Was this post helpful?