[c-nsp] Unidirectional CDP traffic

[Daniel Dib]

On to, mar 31, 2011 at 13:50:33, Gökhan Gümüş wrote:
> Subject: Re: [c-nsp] Unidirectional CDP traffic
> 
> Hi Daniel,
> 
> Thanks for this.
> Actually interfaces are all working as trunk port however they 
> configured like this.
> 
> We cleared counters and made ping tests.
> Please see our test results below,
> 
> 
> Clearing counters:
> 
> 
> === London ===
> LIXCORML01#cle count gi3/16
> Clear "show interface" counters on this interface [confirm] 
> LIXCORML01#p 10.119.44.150
> 
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 10.119.44.150, timeout is 2 seconds:
> .....
> Success rate is 0 percent (0/5)
> 
> LIXCORML01#sh int gi3/16
> 
> GigabitEthernet3/16 is up, line protocol is up (connected)
>   Hardware is Gigabit Ethernet Port, address is 68ef.bd4f.ccd7 (bia
> 68ef.bd4f.ccd7)
>   Description: abc
>   MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
>      reliability 255/255, txload 1/255, rxload 1/255
>   Encapsulation ARPA, loopback not set
>   Keepalive set (10 sec)
>   Full-duplex, 1000Mb/s, link type is force-up, media type is 
> 1000BaseLH
>   input flow-control is on, output flow-control is on
>   ARP type: ARPA, ARP Timeout 04:00:00
>   Last input never, output never, output hang never
>   Last clearing of "show interface" counters 00:00:21
>   Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops:
> 0
>   Queueing strategy: fifo
>   Output queue: 0/40 (size/max)
>   5 minute input rate 0 bits/sec, 0 packets/sec
>   5 minute output rate 1000 bits/sec, 1 packets/sec
>      0 packets input, 287503 bytes, 0 no buffer
>      Received 0 broadcasts (0 multicasts)
>      0 runts, 0 giants, 0 throttles
>      0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
>      0 input packets with dribble condition detected
>      38 packets output, 2720 bytes, 0 underruns
>      0 output errors, 0 collisions, 0 interface resets
>      0 babbles, 0 late collision, 0 deferred
>      0 lost carrier, 0 no carrier
>      0 output buffer failures, 0 output buffers swapped out
> 
> LIXCORML01#sh cdp nei gi3/16
> Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
>                   S - Switch, H - Host, I - IGMP, r - Repeater, P - 
> Phone,
>                   D - Remote, C - CVTA, M - Two-port Mac Relay
> 
> Device ID        Local Intrfce     Holdtme    Capability  Platform
> Port
> ID
> LIXCORML01#
> ===
> 
> === Stockholm ===
> 
> 
> SOXCORML01#cle count gi3/11
> Clear "show interface" counters on this interface [confirm] 
> SOXCORML01#p 10.119.44.149
> 
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 10.119.44.149, timeout is 2 seconds:
> .....
> Success rate is 0 percent (0/5)
> 
> SOXCORML01#sh int gi3/11
> GigabitEthernet3/11 is up, line protocol is up (connected)
>   Hardware is Gigabit Ethernet Port, address is 68ef.bd4f.c51e (bia
> 68ef.bd4f.c51e)
>   Description: abc
>   MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
>      reliability 255/255, txload 1/255, rxload 1/255
>   Encapsulation ARPA, loopback not set
>   Keepalive set (10 sec)
>   Full-duplex, 1000Mb/s, link type is force-up, media type is 
> 1000BaseLH
>   input flow-control is on, output flow-control is on
>   ARP type: ARPA, ARP Timeout 04:00:00
>   Last input 00:00:00, output never, output hang never
>   Last clearing of "show interface" counters 00:00:21
>   Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops:
> 0
>   Queueing strategy: fifo
>   Output queue: 0/40 (size/max)
>   5 minute input rate 0 bits/sec, 0 packets/sec
>   5 minute output rate 0 bits/sec, 0 packets/sec
>      35 packets input, 2910 bytes, 0 no buffer
>      Received 35 broadcasts (35 multicasts)
>      0 runts, 0 giants, 0 throttles
>      0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
>      0 input packets with dribble condition detected
>      53 packets output, 3776 bytes, 0 underruns
>      0 output errors, 0 collisions, 0 interface resets
>      0 babbles, 0 late collision, 0 deferred
>      0 lost carrier, 0 no carrier
>      0 output buffer failures, 0 output buffers swapped out
> 
> SOXCORML01#sh cdp nei gi3/11
> Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
>                   S - Switch, H - Host, I - IGMP, r - Repeater, P - 
> Phone,
>                   D - Remote, C - CVTA, M - Two-port Mac Relay
> 
> Device ID        Local Intrfce     Holdtme    Capability  Platform
> Port
> ID
> LIXCORML01.nd.barcapint.com <http://lixcorml01.nd.barcapint.com/>
>                  Gig 3/11          133             R S I  WS-C4900M Gig
> 3/16
> SOXCORML01#
> ===
> 
> Thanks in advance.
> 
> Gokhan
> 
> 

Traffic is flowing from London to STHLM and STHLM is responding as seen by
counters. If you debug ICMP you should see that STHLM is receving an echo
request and sending an echo reply. However the traffic never makes it back
to London. I think you need to troubleshoot your WDM network. Do you have
any counters available there?

/Daniel