what is NVI0 interface on router

Unanswered Question
Jan 17th, 2010
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Hi all,

on my router i see

NVI0 is up, line protocol is up
  Hardware is NVI
  Interface is unnumbered. Using address of NVI0 (
  MTU 1514 bytes, BW 10000000 Kbit/sec, 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 04:46:27
  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 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out

I have no idea what this interface is used for?

Any answers



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Overall Rating: 0 (1 ratings)
Ganesh Hariharan Sun, 01/17/2010 - 05:46
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Hi Mahesh,

The NVI is only used when using "domain-less" NAT.  It is normal to have the NVI shutdown when not using NVI. NVI allows traffic between overlapped VPN routing/forwarding (VRFs) in the same Provider Edge (PE) router, and traffic from inside to inside between overlapping networks.

check out the attached document regarding NVI hope that clear out your query !!



Claudio Monge Thu, 03/13/2014 - 13:29
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I have the same configuration but Interface Gi0 is UP UP connected with dual T1s and int fa8 is down down with one T1 as backup. The ISP told me the T1 is UP but I see the int fa8 down yet. Is it a normal behavior?


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