Isolating Traffic Interruptions - Cisco Nexus 1000V Troubleshooting Manual

Layer 2 Switching Problems
switchport mode trunk
end
As this output shows, VLANs 1,60-69, 231-233 are allowed on the port. If a particular VLAN is not in
the allowed VLAN list, make sure to add it to the allowed VLAN list of the port.

Isolating Traffic Interruptions

You can isolate the cause for no traffic passing across VMs on different VEMs.
Step 1 In the output of the show port-profile name command, verify the following information:
•
•
switch# show port-profile name alluplink
Inside the VM, verify that the Ethernet interface is up.
Step 2
ifconfig –a
If not, delete that NIC from the VM, and add another NIC.
Using any sniffer tool, verify that ARP requests and responses are received on the VM interface.
Step 3
On the upstream switch, look for the association between the IP and MAC address:
Step 4
debug arp
show arp
Example:
switch# debug arp
ARP packet debugging is on
11w4d: RARP: Rcvd RARP req for 0050.56b7.3031
11w4d: RARP: Rcvd RARP req for 0050.56b7.3031
11w4d: RARP: Rcvd RARP req for 0050.56b7.4d35
11w4d: RARP: Rcvd RARP req for 0050.56b7.52f4
11w4d: IP ARP: rcvd req src
11w4d: RARP: Rcvd RARP req for 0050.56b7.3031
switch#
Example:
switch# show arp
Cisco Nexus 1000V Troubleshooting Guide, Release 5.2(1)SV3(1.1)
12-6
The control and packet VLANs that you configured are present (in the example, these are 3002 and
3003).
If the physical NIC in your configuration carries the VLAN for the VM, that VLAN is also present
in the allowed VLAN list.
port-profile alluplink
description:
status: enabled
system vlans: 3002,3003
port-group: alluplink
config attributes:
switchport mode trunk
switchport trunk allowed vlan 1,80,3002,610,620,630-650
no shutdown
evaluated config attributes:
switchport mode trunk
switchport trunk allowed vlan 1,80,3002,3003,610,620,630-650
no shutdown
assigned interfaces:
Ethernet2/2
10.78.1.123 0050.564f.3586
Chapter 12 Layer 2 Switching
, dst 10.78.1.24 Vlan3002
OL-31593-01