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New Member

Troubleshhoting interfaz PA-FE-TX

Hi Friends

I have a problem with a network interface card PA-FE-TX on a 7206VXR router, the interface is currently operating in half duplex mode, this interface is connected to a Fast Ethernet port on a DSLAM where my clients are connected (CPEs ) but I can not change the operating mode to full duplex on the interface of the router 7206, because this causes the upload speed of customers affected by this change. I changed the network cable and the problem persists then you can see the show interfaces command output Fast Ethernet:

Should I replace the interface?

a.headend#show interfaces fastEthernet 1/0
FastEthernet1/0 is up, line protocol is up
  Hardware is DEC21140A, address is 00d0.bc5f.101c (bia 00d0.bc5f.101c)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 24/255, rxload 3/255
  Encapsulation 802.1Q Virtual LAN, Vlan ID  1., loopback not set
  Keepalive set (10 sec)
  Half-duplex, 100Mb/s, 100BaseTX/FX
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters 1y10w
  Input queue: 0/75/0/26 (size/max/drops/flushes); Total output drops: 4040
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 2794000 bits/sec, 1456 packets/sec
  5 minute output rate 13088000 bits/sec, 1692 packets/sec
     2795496400 packets input, 174770775 bytes
     Received 1979825 broadcasts, 0 runts, 1721 giants, 1 throttles
     15831631 input errors, 15831459 CRC, 0 frame, 0 overrun, 172 ignored
     0 watchdog
     0 input packets with dribble condition detected
     3512311051 packets output, 3028779696 bytes, 0 underruns
     13 output errors, 14867511 collisions, 7 interface resets
     0 babbles, 0 late collision, 0 deferred
     12 lost carrier, 6 no carrier
     0 output buffer failures, 0 output buffers swapped out

Thanks for your help!!!


VIP Super Bronze

Re: Troubleshhoting interfaz PA-FE-TX

Hello Marcelo,

When you have duplex mismatch, you will have slow performance and it can cause intermittent connectivity, and loss of connection

You also have a lot of CRC error which is caused by the duplex mismatch.

If you have already changed the cable, then it may be a faulty card.  It there any way for you to set the duplex to full and see what happens?



New Member

Re: Troubleshhoting interfaz PA-FE-TX

Hi  Reza

That was what I did, however like I said earlier, when I change the operating mode to full duplex, the upload speed decreases in the CPEs

Thanks for your help!


Hall of Fame Super Gold

Re: Troubleshhoting interfaz PA-FE-TX

You have many input errors, that indicates the device to which you are connecting is faulty.