Weird interface on a 2610XM... "NVI0"

[d.wingert]

Hello Netpro,

I discovered an interface called "NVI0" on an 2610xm running with IOS "c2600-spservicesk9-mz.123-14.T3.bin"

I wasn't able to find any documentation about this interface type, does anyone know what this interface is about?

It doesn't show up in the running config, I can't delet it, I can't clear it...

It is just visible with "show ip interface brief" and "show interface"

NVI0 is up, line protocol is up

Hardware is NVI

MTU 1514 bytes, BW 10000000 Kbit, DLY 0 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation UNKNOWN, loopback not set

Last input never, output never, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

0 packets input, 0 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

0 packets output, 0 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

Regards, Dirk.

[Richard Burts · Accepted solution]

Dirk

A quick look at the documentation reveals that the NVI is the NAT Virtual Interface which was apparently introduced in 12.3(14)T. With this new feature you no longer need to configure NAT inside interface(s) and NAT outside interface(s). So yes you would not be able to delete it, since it is defaulted into existance by this version of IOS.

This link will provide more information about this new feature:

http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/products_feature_guide09186a008041d91a.html

HTH

Rick

[d.wingert]

Hello Rick,

I was just searching for "NVI0" and couldn't find anything. Thanks for your help!

I will then allow NVI0 to make itself at home on my routers. :-)

Regards, Dirk.