%NAT is not supported on GigabitEthernet0

[qsosan20]

Hello Experts ,

Am trying to configure nat on newly installed fiber connection at GigabitEthernet0 , how ever am getting below error : 

(config)#ip nat inside source list 103 interface GigabitEthernet0.10 overload
%NAT is not supported on GigabitEthernet0

Interface config : 

interface GigabitEthernet0.10
encapsulation dot1Q 10
ip address x.x.x.x
ip nat outside

Is it because of Gig0 in VRF mgmt ? 

#sh vrf
Name Default RD Protocols Interfaces
Mgmt-intf <not set> ipv4,ipv6 Gi0

If yes how i can overcome this , as the only interface that support SFP is Gig 0 ,

l#sh inventory

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
INFO: Please use "show license UDI" to get serial number for licensing.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

NAME: "Chassis", DESCR: "Cisco ISR4321 Chassis"
PID: ISR4321/K9 , VID: V05 ,

l#sh version
Cisco IOS XE Software, Version 16.06.04

[Jens Albrecht · Accepted solution]

Hello @qsosan20,

you tried to configure NAT on the Mgmt interface and wrote "... as the only interface that support SFP is Gig 0" but that's not correct.

The SFP port is Gig0/0/0 as you can see below and this port can be configured for NAT without any problems.

HTH!

[qsosan20]

Hi Jens,

Thanks a lot for the clarification — that makes perfect sense now.

I was double-checking behavior across different ISR interfaces and wanted to confirm if there were any exceptions or recent changes related to NAT support. Your input confirms what I suspected and helps me close the loop on this.