Problem in router 2900

[Mohammed Aswath Ali]

     Hi all,

   we have a cisco 2900 router ,in which one interface is connected to internet ISP and another interface is connected to LAN .

Till morning everything is working fine ,but from afternoon internet is not working .i checked with ISP they said no problem with their end .so i logged into router and do some troubleshoot .

I am not able to ping my outside interface ip from my router iteself . The outside interface is a multilink interface which is formed by bundling two serial interface's

So need help to solve this .

[daniel.dib]

Are you saying that you are trying to ping the interface from the router itself? That does not always work.

Which encapsulation are you running? Can you post relevant configs.

Nothing in the logs that indicate that something happened at that point of time? No changes done at that time?

Daniel Dib
CCIE #37149

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[Richard Burts]

Since the original post tells us that "The outside interface is a multilink interface which is formed by bundling two serial interface's"  it is most likely that the encapsulation is ppp. But it would be helpful if the original poster would verify this. To troubleshoot this issue it would be a good place to start if the original poster would post the output of show interface for both the physical serial interfaces and the multilink interface. It would also be good information to have if the original poster would tell us whether he is able to ping the address of the ISP router on this connection.

HTH

Rick

[Mohammed Aswath Ali]

output of  "show interface" command....

Router-3600#show int

Router-3600#show interfaces s0/0/0

Serial0/0/0 is up, line protocol is up

  Hardware is WIC MBRD Serial

  MTU 1500 bytes, BW 1544 Kbit/sec, DLY 20000 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation PPP, LCP Open, multilink Open

  Link is a member of Multilink bundle Multilink1, loopback not set

  Keepalive set (10 sec)

  Last input 00:21:03, output 00:00:01, output hang never

  Last clearing of "show interface" counters 00:42:14

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 4

  Queueing strategy: weighted fair  [suspended, using FIFO]

  FIFO output queue 0/40, 4 drops

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 1000 bits/sec, 2 packets/sec

     511 packets input, 9474 bytes, 0 no buffer

     Received 0 broadcasts (0 IP multicasts)

     190 runts, 0 giants, 0 throttles

     910 input errors, 516 CRC, 0 frame, 0 overrun, 0 ignored, 204 abort

     4785 packets output, 282172 bytes, 0 underruns

     0 output errors, 0 collisions, 1 interface resets

     1 unknown protocol drops

     0 output buffer failures, 0 output buffers swapped out

     8 carrier transitions

     DCD=up  DSR=up  DTR=up  RTS=up  CTS=up

--More--                          

Router-3600#show interfaces s0/0/1

Serial0/0/1 is up, line protocol is up

  Hardware is WIC MBRD Serial

  MTU 1500 bytes, BW 1544 Kbit/sec, DLY 20000 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation PPP, LCP Open, multilink Open

  Link is a member of Multilink bundle Multilink1, loopback not set

  Keepalive set (10 sec)

  Last input 00:21:16, output 00:00:07, output hang never

  Last clearing of "show interface" counters 00:42:28

  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 17

  Queueing strategy: weighted fair  [suspended, using FIFO]

  FIFO output queue 0/40, 17 drops

  5 minute input rate 0 bits/sec, 0 packets/sec

  5 minute output rate 0 bits/sec, 0 packets/sec

     516 packets input, 9448 bytes, 0 no buffer

     Received 0 broadcasts (0 IP multicasts)

     0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

     4903 packets output, 288801 bytes, 0 underruns

     0 output errors, 0 collisions, 1 interface resets

     0 unknown protocol drops

     0 output buffer failures, 0 output buffers swapped out

     6 carrier transitions

     DCD=up  DSR=up  DTR=up  RTS=up  CTS=up

--More--                          

Router-3600#

Router-3600#show interfaces multilink 1

Multilink1 is up, line protocol is up

  Hardware is multilink group interface

  Internet address is 218.248.18.113/30

  MTU 1500 bytes, BW 3088 Kbit/sec, DLY 20000 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation PPP, LCP Open, multilink Open

  Stopped: CDPCP

  Open: IPCP, loopback not set

  Keepalive set (10 sec)

  DTR is pulsed for 2 seconds on reset

  Last input 00:21:53, output never, output hang never

  Last clearing of "show interface" counters 00:43:08

  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 0 bits/sec, 0 packets/sec

  5 minute output rate 1000 bits/sec, 3 packets/sec

     31 packets input, 2634 bytes, 0 no buffer

     Received 0 broadcasts (0 IP multicasts)

     0 runts, 0 giants, 0 throttles

     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

     8777 packets output, 564958 bytes, 0 underruns

     0 output errors, 0 collisions, 3 interface resets

     0 unknown protocol drops

     0 output buffer failures, 0 output buffers swapped out

     0 carrier transitions

Router-3600#

[daniel.dib]

The interface is up and there have been packets received both inbound and outbound. The bundle is up and LCP is open. IPCP is open as well so it seems that PPP negotiation is working.

Can you ping 218.248.18.114? What happens if you try to ping/traceroute something like 8.8.8.8? What configuration do you have PPP?

Daniel Dib
CCIE #37149

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