Isolating network problems on Lenovo switches

Switch transceiver status

Use the following commands to check the transceiver status on Lenovo switches:

• RackSwitch G8052 (ENOS): show interface transceiver

• All the other Lenovo switches: display interface transceiver

Port troubleshooting

Use the following procedure to troubleshoot a port issue on Lenovo switches.

1. Check the physical connection of the cable to the port. If necessary, reconnect the cable.

2. Use the relevant CNOS/ENOS command to check the transceiver status on a Lenovo switch.

   • RackSwitch G8052 (ENOS): show interface transceiver

   • All other Lenovo switches (CNOS): display interface transceiver

3. If necessary, use the relevant command to disable or enable the port.

   • RackSwitch G8052 (ENOS):

     1. Use interface port <port_number> to enter interface configuration mode.

     2. Use shutdown to disable the port.

     3. Use no shutdown to enable the port.

   • All other Lenovo switches (CNOS):

     1. Use interface eth 1/<port_number> to enter interface configuration mode.

     2. Use shutdown to disable the port.

     3. Use no shutdown to enable the port.

Spanning Tree troubleshooting

Use the following procedure to troubleshoot a Spanning Tree port issue on Lenovo switches.

1. Use the following commands to check the Spanning Tree port status:

   • RackSwitch G8052 (ENOS): show spanning-tree

   • All other Lenovo switches (CNOS): display spanning-tree

2. Use the following commands to verify whether Spanning Tree is disabled on uplink ports:

   • RackSwitch G8052 (ENOS): show running-config

   • All other Lenovo switches (CNOS): show spanning-tree mst interface ethernet 1/<port_number>

VLAN troubleshooting

Use the following procedure to troubleshoot a VLAN issue on Lenovo switches.

1. Use the following commands to verify that VLANs have been created and are active:

   • RackSwitch G8052 (ENOS): show vlan

   • All other Lenovo switches (CNOS): display vlan summary

2. Use the vlan <vlan_ID> command to enter VLAN configuration mode.

3. Use the shutdown command to disable the VLAN.

4. Use the no shutdown command to enable the VLAN.

5. Use the interface <interface_name> to enter the interface configuration mode.

6. Use the following commands to check the trunk port setting for tag/untag observations:

   • RackSwitch G8052 (ENOS): switchport trunk allowed vlan <add/remove> <vlan_ids>

   • All other Lenovo switches (CNOS): bridge-port trunk allowed vlan <add/remove> <vlan_ids>

IP troubleshooting

Use the following procedure to troubleshoot an IP issue on Lenovo switches.

1. Confirm that the correct IPs and subnet masks are defined on the relevant interfaces:

   • RackSwitch G8052 (ENOS): show interface ip

   • All other Lenovo switches (CNOS): display running-config ip

2. Use the display ip interface brief command on the Lenovo switches running CNOS to verify whether the link status is UP for all IP interfaces.

Management network troubleshooting

Use the following procedure to troubleshoot a management network issue on Lenovo switches.

1. Check the management IP interface and gateway:

   • RackSwitch G8052 (ENOS): show interface ip or show ip gateway 1

   • All other Lenovo switches (CNOS): display ip interface or display run vrf management

2. Confirm whether the RackSwitch G8272 switches can ping the gateway: ping <G8052_management_port_IP> vrf management

3. Verify the IP ARP table for the management interface:

   • RackSwitch G8052 (ENOS): show ip arp

   • All other Lenovo switches (CNOS): display ip arp vrf management

4. Check the management port state.

vLAG troubleshooting

Use the following procedure to the troubleshoot vLAG issues on the RackSwitch G8272 switches.

1. Ensure that the port channel is UP and active.

2. Ensure that the port channel type (static or dynamic) on both ends is identical.

3. Use the CNOS command display port-aggregation summary to ensure that all port-channel are UP in port-aggregation.

4. Use the CNOS command display vlag information to ensure that vLag ISL is enabled, UP, and active. Also, check to see that the vLag peer-id on both RackSwitch G8272 switches are the same.