Serial interface connectivity problems

[matthias7]

Hi

We have an T1 leased line between 2 routers, let me tell you from the start i am no Cisco Expert but an happy new bee wanting to
find out why it is happening and what is the main cause, i am familiar with cisco and commands.

The client is complain it that the internet slows down in the afternoon but i find yesterday that i looses connection with cisco router on the client premesis.

what i find so far:

router one uses serial x/x/x:0 and says upon interface status for the serial port that amount of packet droped on the out interface is xxxxxx ...

okey connects remotely to remote cisco router when still having connection that goes down every 5 minutes and comes back up for 2 minutes and goes down again, "show version" says been up for several weeks. so power outage is not an issue ...


what is the next step to make the right conclusions next ??

Matt

 

[matthias7]

Hi

More data that i got and forget to mention ...

The cisco router with serial interface x/x/x:0 says when other cisco router on the other side of the T1 line is not responding that serialx/x/x:0 is down and line protocol is down and when remote router resons it says that serialx/x/x:0 is up and linme is up meaning OSI level 1,2,3 is working again ...

so why do i have connectivity issues now that have been working before for months and how do i evaluate bandwidth problems as well ...

matt

 

[matthias7]

Hi

This is he output from show interface serial x/x/x:0 when no connction with client cisco router
********************************************

Serialx/x/x:0 is down, line protocol is down
Hardware is xxxxx Serial
Internet address is xxx.xxx.xxx.xxx/30
MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,
reliability 254/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input 00:19:22, output 00:19:23, output hang never
Last clearing of "show interface" counters 00:56:36
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 272
Queueing strategy: weighted fair
Output queue: 0/1000/64/54 (size/max total/threshold/drops)
Conversations 0/256/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1152 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
92502 packets input, 15751124 bytes, 0 no buffer
Received 253 broadcasts, 0 runts, 3 giants, 0 throttles
1129 input errors, 1129 CRC, 527 frame, 242 overrun, 0 ignored, 719 abort
117205 packets output, 86402826 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
7 carrier transitions
Timeslot(s) Used:1-24, SCC: 0, Transmitter delay is 0 flags
router#show interfaces serial x/x/x:0
Serialx/x/x:0 is down, line protocol is down
Hardware is xxxxxx Serial
Internet address is xxx.xxx.xxx.xxx/30
MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,
reliability 254/255, txload 1/255, rxload 1/255
Encapsulation HDLC, loopback not set
Keepalive set (10 sec)
Last input 00:36:16, output 00:36:17, output hang never
Last clearing of "show interface" counters 01:13:30
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 272
Queueing strategy: weighted fair
Output queue: 0/1000/64/54 (size/max total/threshold/drops)
Conversations 0/256/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1152 kilobits/sec
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
92502 packets input, 15751124 bytes, 0 no buffer
Received 253 broadcasts, 0 runts, 3 giants, 0 throttles
1129 input errors, 1129 CRC, 527 frame, 242 overrun, 0 ignored, 719 abort
117205 packets output, 86402826 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
7 carrier transitions
Timeslot(s) Used:1-24, SCC: 0, Transmitter delay is 0 flags
***********************************************


seems like i have to restart the interface and see ifi t solvs it ...



matt
*********************************************

 

[Rouky]

are you directly connected between the two Cisco routers ? you receive a clock ?

 

[matthias7]

Hi

I am entering in from the ethernet interface on the router that have the serial x/x/x:0 that i can reach at all time and then from that router an leased T1 line to the other router that i can reach and log in for 2 minutes and then went down and comes up again and goes down ...

today the router have been behaving well no down time or so but then again what was the reason to that happening and how do i trouble shoot if i have bandwidth issue when working good ...

Sorry 2 questions in one:

why did i have connectivity issues and today it works like an charm ...

2

the client tells me that the usable bandwidth goes down in the afternoon but good during the day ...


Matt