Cisco Router NAT NVI0 always up when it creates nat statement.

[mhiyoshi]

Dear Support Team

I have a question about the NAT NVI0 interface. If I configures static nat statement the NVI0 interface creates and always up
But it can not shutdown or remove except reload. Is it just specification and no impact if NVI0 always up?
or I appreciate if you can let me know any other solution.

The symptoms show s below.

C891FJ#(config)#ip nat inside source static 1.1.1.1 2.2.2.2
C891FJ#(config)#end
C891FJ#
*Feb 27 09:26:41.935: %LINEPROTO-5-UPDOWN: Line protocol on Interface NVI0, changed state to up
C891FJ#
*Feb 27 09:26:43.539: %SYS-5-CONFIG_I: Configured from console by console
C891FJ#sh ip int brief | in up
NVI0 unassigned NO unset up up
C891FJ#conf t
Enter configuration commands, one per line. End with CNTL/Z.
C891FJ(config)#no ip nat inside source static 1.1.1.1 2.2.2.2
C891FJ(config)#end
C891FJ#
C891FJ#sh ip int b
*Feb 27 09:26:57.487: %SYS-5-CONFIG_I: Configured from console by console
C891FJ#sh ip int brief | in up
NVI0 unassigned NO unset up up
C891FJ#

Best Regards,

Masanobu Hiyoshi

[Mark Malone]

Hi that's expected when you use NAT it creates a NAT virtual interface , nothing  to worry about see doc for further explanation on this interface

https://supportforums.cisco.com/sites/default/files/legacy/0/8/0/60080-NAT%20Virtual%20Interface.pdf

[mhiyoshi]

Hello Mark

Oh I see this is expected behavior. Thank you for your great support!

Best Regards,

Masanobu Hiyoshi