Vlan interface "unknown protocol drops"

[Steve Coady]

Hello

I have a satellite office that connects via VPN back to my Corporate office.

The VPN is terminated on an Cisco 891.

I have received complaints from the user's there that their Citrix session hangs on them. They can then reconnect the session and

find the session was still going as they started back where they left off. There are several pc's that experiewnce the same issue.

The Citrix server has been checked out. The PC's have been checked out and re-imaged just to make sure.

I see on the Vlan interfacfe on the 9891 there are alot of unknown protocol drops.

What does this mean and could it be the cause of the session hang?

Vlan10 is up, line protocol is up
  Hardware is EtherSVI, address is 4403.abcd.efgh (bia 4403.abcd.efgh)
  Internet address is 10.x.221.1/24
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not supported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:05, output never, output hang never
  Last clearing of "show interface" counters 22:43:53
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 1000 bits/sec, 1 packets/sec
  5 minute output rate 1000 bits/sec, 1 packets/sec
     218197 packets input, 33432444 bytes, 0 no buffer
     Received 6568 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     189384 packets output, 79892307 bytes, 0 underruns
     0 output errors, 0 interface resets
     7433 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out

[prcsdm001 · Accepted solution]

Hi,

The unknown protocol drops can be caused by DTP, CDP or LLDP protocols which are not enabled on your router. These is not a problem and you can ignore it. I would check the physical interface too and performance on the satellite connection.

Regards,

Adam

[Steve Coady]

Adam

Thank you for the response.

[Joseph W. Doherty]

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Posting

If you're running Citrix across a VPN, that crosses the Internet (?), I would be first concerned about transient latency and/or packet drops.  I would also be concerned whether your VPN has been configured to avoid packet fragmentation.