12-23-2013 09:10 PM - edited 03-04-2019 09:55 PM
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 .
12-23-2013 11:37 PM
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
Please rate helpful posts.
12-24-2013 08:48 AM
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
12-25-2013 08:21 PM
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#
12-25-2013 10:46 PM
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
Please rate helpful posts.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide