DHCP snooping on 3750 FE port but not on GE port - why?

[jkeeffe]

I have a 3750 switch (c3750-ipservicesk9-mz.122-55.SE3) that I am configuring DHCP snooping on.

I can configure dhcp snooing trust on a FE port, but can't on a GE uplink port - there is no snooping option under that interface as you can see below.

VoIP-MDF-RS3750(config)#int f1/0/47
VoIP-MDF-RS3750(config-if)#ip dhcp ?
  client    DHCP client configuration
  limit     Limit DHCP Lease
  relay     DHCP relay configuration parameters
  server    Configure DHCP server behavior
  snooping  DHCP Snooping

VoIP-MDF-RS3750(config-if)#int g1/0/1
VoIP-MDF-RS3750(config-if)#ip dhcp ?
  client  DHCP client configuration
  limit   Limit DHCP Lease
  relay   DHCP relay configuration parameters
  server  Configure DHCP server behavior

VoIP-MDF-RS3750(config-if)#ip dhcp

How do I trust the GE uplink of the switch for DHCP snooping?

[jkeeffe · Accepted solution]

I figured out why the GE port doesn't allow for 'ip dhcp snooping trust'.  Only an L2 port can have dhcp snooping trust on it - an L3 port doesn't have that option.  I had an IP address configured on the GE port, therefore no snooping trust option was available.

[Rajeev Sharma]

Hey,

Configure the command switchport under Gig interface and then you should be able to configure snooping trust.

Regards,
RS