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Enhanced show interfaces command

It's amazing how many options (most of them still undocumented) the show interfaces command accepts in IOS release 12.4T (I won't even start guessing when each one was introduced, if you're running old IOS releases, please feel free to comment):

  • show interfaces description displays interface names, L1 and L2 status (line and line-protocol status) and interface description. Extremely handy if you want to check which interfaces are up/down.
  • show interfaces counters protocol status displays the L3 protocols active on each interface.
  • show interfaces summary displays the state of various interface queues and related drop counters in a nice tabular format.
  • show interfaces accounting displays per-protocol in/out counters.

Here are a few sample printouts:

a1#show interfaces description
Interface Status Protocol Description
Fa0/0 up up Central LAN
Fa0/1 admin down down
Se0/0/0 up up Frame Relay
Se0/0/0.100 up up Link to B1
Se0/1/0 admin down down
Se0/1/1 admin down down
Lo0 up up
a1#show interfaces counters protocol status
Protocols allocated:
 FastEthernet0/0: Other, IP, DEC MOP, ARP, CDP
 FastEthernet0/1: Other, IP
 Serial0/0/0: Other, IP, CDP
 Serial0/1/0: Other, IP
 Serial0/1/1: Other, IP
 Loopback0: Other, IP
 VoIP-Null0: Other, IP
a1#show interfaces summary
 *: interface is up
 IHQ: pkts in input hold queue IQD: pkts dropped from input queue
 OHQ: pkts in output hold queue OQD: pkts dropped from output queue
 RXBS: rx rate (bits/sec) RXPS: rx rate (pkts/sec)
 TXBS: tx rate (bits/sec) TXPS: tx rate (pkts/sec)
 TRTL: throttle count
* FastEthernet0/0 0 0 0 0 0 0 0 0 0
  FastEthernet0/1 0 0 0 0 0 0 0 0 0
* Serial0/0/0 0 0 0 0 0 0 0 0 0
* Serial0/0/0.100 - - - - - - - - -
  Serial0/1/0 0 0 0 0 0 0 0 0 0
  Serial0/1/1 0 0 0 0 0 0 0 0 0
* Loopback0 0 0 0 0 0 0 0 0 0
NOTE:No separate counters are maintained for subinterfaces
     Hence Details of subinterface are not shown
a1#show interfaces accounting
FastEthernet0/0 Central LAN
      Protocol Pkts In Chars In Pkts Out Chars Out
         Other 0 0 490 29400
            IP 2737 216847 3052 424422
       DEC MOP 0 0 8 616
           ARP 5 316 12 720
           CDP 82 30914 84 29563
Interface FastEthernet0/1 is disabled
Serial0/0/0 Frame Relay
      Protocol Pkts In Chars In Pkts Out Chars Out
         Other 0 0 490 6370
            IP 515 43748 1034 87608
           CDP 83 26477 168 55272


  1. On switches (12.2S code), show int status is nice:

    Port Name Status Vlan Duplex Speed Type
    Gi1/1 [sfmdf1] connected trunk full 1000 1000BaseSX
    Gi1/2 [sfmdf2] connected trunk full 1000 1000BaseSX
    Gi1/3 [cr2mdf1] connected trunk full 1000 1000BaseLH
    Gi1/4 [chphs2mdf] connected trunk full 1000 1000BaseLH
    Gi1/5 [hccx5mdf] connected trunk full 1000 1000BaseLH
    Gi1/6 [chmdf] connected trunk full 1000 1000BaseLH

  2. 1) sh interfaces description
    2) sh interfaces counters protocol status
    3) sh interfaces summary
    4) sh interfaces accounting

    a) IOS (tm) C3500XL Software (C3500XL-C3H2S-M), Version 12.0(5)WC17, RELEASE SOFTWARE (fc1)
    b) IOS (tm) 2500 Software (C2500-IS-L), Version 12.3(24), RELEASE SOFTWARE (fc4)
    c) Cisco IOS Software, C2600 Software (C2600-ADVSECURITYK9-M), Version 12.4(17a), RELEASE SOFTWARE (fc2)
    d) IOS (tm) C2950 Software (C2950-I6K2L2Q4-M), Version 12.1(22)EA10a, RELEASE SOFTWARE (fc2)

    a: 1 - works, but everything is printed in one line (ugh!), 2 - does not work, 3 - does not work, 4 - OK
    b: 1 - OK, 2 - does not work, 3 - OK, 4 - OK
    c: 1 - OK, 2 - OK, 3 - OK, 4 - OK
    d: 1 - OK, 2 - does not work, 3 - OK, 4 - OK

  3. a:1 that's common thing about 3500 - you won't be able to repair it by new software - not bug, but feature :-((

  4. Hi Ivan,

    I was configuring a WAN router this morning and I couldn't manage to obtain separate counters for subinterfaces... I know that your post is 4 years ago, but the question is still there.

    Thanks for your answer.


  5. Ivan Pepelnjak23 May, 2011 09:58

    Subinterfaces are logical interfaces and thus don't have the full set of counters associated with them.

    You might get some data out of QoS counters; you definitely won't see queue lengths, errors or drops.

  6. Thanks Ivan, your entire blog is very useful. It's so good that people copy & paste entire articles"forgetting" to credit the source:

    One comment on "show interfaces counters protocol status": there are both Layer 2/3 protocols listed by this command.

  7. Hi Ivan,

    Kind of offtopic.
    Do you have any preferences for the character used for the description command?

    Like *** or --- ?


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Ivan Pepelnjak, CCIE#1354 Emeritus, is an independent network architect. He has been designing and implementing large-scale data communications networks as well as teaching and writing books about advanced technologies since 1990. See his full profile, contact him or follow @ioshints on Twitter.