troubleshooting Question

T1 CRC errors, router unresponsive

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rperry_wha asked on
Networking Hardware-Other
8 Comments1 Solution720 ViewsLast Modified:
I've been trying to add in some QoS on our router.  Last night everything was fine when I left, but then today the router was unresponsive - even on the console, until I disconnected the T1 line (s0/0).  I'm seeing many errors and this happens every time I plug the line back in.  I've removed my QoS for the moment to try and diagnose the issue.  
Serial0/0 is down, line protocol is down 
  Hardware is PQUICC with Fractional T1 CSU/DSU
  Description: T-1 to Supranet
  Internet address is
  MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, 
     reliability 240/255, txload 1/255, rxload 1/255
  Encapsulation PPP, LCP Closed, loopback not set
  Keepalive set (10 sec)
  Last input never, output 00:00:07, output hang never
  Last clearing of "show interface" counters 00:04:22
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: weighted fair
  Output queue: 0/1000/64/0 (size/max total/threshold/drops) 
     Conversations  0/1/256 (active/max active/max total)
     Reserved Conversations 0/0 (allocated/max allocated)
     Available Bandwidth 1158 kilobits/sec
  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, 1 giants, 0 throttles
     1040186 input errors, 453896 CRC, 420518 frame, 0 overrun, 10179 ignored, 165771 abort
     2 packets output, 28 bytes, 0 underruns
     0 output errors, 0 collisions, 9 interface resets
     0 output buffer failures, 0 output buffers swapped out
     2 carrier transitions
     DCD=down  DSR=up  DTR=up  RTS=up  CTS=down
show run:
interface Serial0/0
 description T-1 to Supranet
 ip address
 encapsulation ppp
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