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CISCO 4331 - Cannot ping directly connected interface after 24-24hHrs.

Posted on 2016-09-25
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Last Modified: 2016-10-15
Our Cisco 4331 router works fine for about 24-48 hours then the WAN interfaces 'stop' working.

Ie. from the router's IOS I cannot ping the Public IP address of the interface.

It was all working fine this morning but -

Right now I cannot ping 69.161.211.94 on GE0/0/2  - despite the IP address  being directly bound to the routers interface.

After a reload it'll all start working.

What could be causing this? What data can I collect to debug etc?

 
69.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
C        69.161.211.72/30 is directly connected, GigabitEthernet0/0/1
L        69.161.211.74/32 is directly connected, GigabitEthernet0/0/1

C        69.161.211.92/30 is directly connected, GigabitEthernet0/0/2
L        69.161.211.94/32 is directly connected, GigabitEthernet0/0/2

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GigabitEthernet0/0/2 is up, line protocol is up
  Hardware is ISR4331-3x1GE, address is 5897.bdb6.5162 (bia 5897.bdb6.5162)
  Description: -- TPG 100/40 NBN Voice VPN ---
  Internet address is 69.161.211.94/30
  MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not supported
  Full Duplex, 1000Mbps, link type is auto, media type is T
  output flow-control is off, input flow-control is off
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 05:42:20, output 00:00:00, output hang never
  Last clearing of "show interface" counters never
  Input queue: 376/375/5110/1 (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 0 bits/sec, 0 packets/sec
     248622 packets input, 68119881 bytes, 0 no buffer
     Received 196 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     136489 packets output, 33267764 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

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AJ
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Question by:Andrew Josephson
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3 Comments
 
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Expert Comment

by:strivoli
Comment Utility
Is it running latest firmware? I understand it was working since a couple of days ago, but checking if it's updated it's worth it.
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Accepted Solution

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Andrew Josephson earned 0 total points
Comment Utility
Anyone notice the Input Queue was at its max???

Input queue: 376/375/5110/1 (size/max/drops/flushes); Total output drops

This caused the interfaces to stop...

http://blogs.cisco.com/security/cisco_ios_queue_wedges_explained
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Author Closing Comment

by:Andrew Josephson
Comment Utility
temporary workaround, :

1.      Increase the hold queue.

config t
int giX/X/X
hold-queue 4096 in

2.      Applied acl on the interface to block the packets causing issue.

ip access-list extended BLOCK_NTP
permit udp <ADDRESS_OF_VALID_NTP_SERVER> any eq ntp
deny udp any any eq 123
permit ip any any
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