Proper SNMP ifType for VLAN

Unanswered Question
Joe Clarke Thu, 03/27/2008 - 13:19
User Badges:
  • Cisco Employee,
  • Hall of Fame,

    Founding Member

If the encapsulation on the VLAN interfaces is ARPA, then the ifType will be ethernetCsmacd(6) for this device in this version of IOS.


We have vlan4 configured thusly;

interface Vlan4

description DCN LAN

bandwidth 10000

ip address

ip access-group NCM_Network_In in

no ip mroute-cache


service-policy output NCM_In


We also have

interface FastEthernet0/0

description Central Switch Gi0/1

no ip address

no ip mroute-cache

duplex full

speed 100

no cdp enable

service-policy output Theatre_In


The vlan4 interface has the same MAC Address as FastEthernet0/0 and both are ifType=6. We are using Smarts Availability Manager for fault managment and it is not able to build topology (connections between switches) properly. According to Smarts this is because two physical interfaces (identified by ifType = 6) have the same MAC address.

Does ifType 6 mean a physical address and therefore the vlan should not be a type 6?



Joe Clarke Thu, 03/27/2008 - 14:20
User Badges:
  • Cisco Employee,
  • Hall of Fame,

    Founding Member

I don't see how you're tying VLAN 4 to interface Fa0/0. It would be helpful to see the entire config from this device as well as a show ver. It looks like you are configuring a switch and not a 2811 router. Is this an etherswitch module in the 2811?


This Discussion