Log when ADSL connection goes down

Answered Question
May 30th, 2007
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Hi,


A remote office keeps complaining that they are losing their internet access. I never seem to be able to catch the problem whilst it's happening, so I was wondering if I can setup their cisco 877 to log when the internet connection drops. Can anyone tell be what I need to do to set this up?


Cheers,

A

Correct Answer by mohammedmahmoud about 9 years 12 months ago

Hi,


Logging on Cisco routers can be in one of these 4 methods:


1.The console by default ("logging console" under the global configuration) - The logging will pop-up to the terminal when you are connected via console.

2.The current terminal line (to the vty sessions when "terminal monitor" is enabled - to disable use "terminal no monitor" - Exec mode not configuration mode) - pop-up logging on you screen like in the first method but it is not enabled by default (needs the "terminal monitor").


3.The router internal logging buffer (use "logging buffered" then "show logging" to display the logs saved in the logging buffer (router internal buffer), but the main drawbacks here is the limited size of the buffer and that the log is lost if the router reloads).


4.The syslog server (use "logging ") the most preferred method, its only drawback is when the connectivity is lost with the syslog server.


I always use a combination of all these methods according to the case.


I hope that i've been informative.


HTH, please do rate all helpful replies,

Mohammed Mahmoud.

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mohammedmahmoud Wed, 05/30/2007 - 14:00
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Hi,


You can use "logging event {link-status | subif-link-status}" under the interface, and then use "show logging", and make sure that you've enabled logging via "logging buffered" in the global configuration.



HTH, please do rate all helpful replies,

Mohammed Mahmoud.

alunemanuel Wed, 05/30/2007 - 23:14
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Hi Both,


Thanks for your quick response. I'm not familiar with logging on cisco's - where is the log file kept and how can it be interpretted? Do you have to use syslog?


-A

Correct Answer
mohammedmahmoud Wed, 05/30/2007 - 23:25
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Hi,


Logging on Cisco routers can be in one of these 4 methods:


1.The console by default ("logging console" under the global configuration) - The logging will pop-up to the terminal when you are connected via console.

2.The current terminal line (to the vty sessions when "terminal monitor" is enabled - to disable use "terminal no monitor" - Exec mode not configuration mode) - pop-up logging on you screen like in the first method but it is not enabled by default (needs the "terminal monitor").


3.The router internal logging buffer (use "logging buffered" then "show logging" to display the logs saved in the logging buffer (router internal buffer), but the main drawbacks here is the limited size of the buffer and that the log is lost if the router reloads).


4.The syslog server (use "logging ") the most preferred method, its only drawback is when the connectivity is lost with the syslog server.


I always use a combination of all these methods according to the case.


I hope that i've been informative.


HTH, please do rate all helpful replies,

Mohammed Mahmoud.

guruprasadr Wed, 05/30/2007 - 23:47
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HI, [PLS RATE / VOTE if Helps]


Logs will be stored in Cisco device itself as History in local RAM Buffer.Its of a fixed size & retains only for newest Information. On low-end routers, a reasonable buffer size might be 16384 or 32768 bytes. On high-end routers with lots of memory (and many logged events), even 262144 bytes might be appropriate. You can issue the "show memory" command to make sure that your router has enough free memory to support a logging buffer. Issue the "logging buffered buffer-size" configuration command in order to create the buffer.


Note: you can see logs in the Device using "show log" command.


Most larger installations have syslog servers. You can send logging information to a server with the logging server-ip-address.


FYI:"Kiwi Syslog Daemon" is a freeware Syslog Daemon for Windows. It receives, filters, logs, displays and forwards Syslog messages and SNMP traps from hosts such as routers, switches, Unix hosts and any other syslog enabled device.


Use command in cisco device to specify the NMS Server / SYSLOG Server:

#logging

Eg: # logging <192.168.5.120>


I hope this will help you in Understanding.


PLS RATE / VOTE if Helps


Best Regards,


Guru Prasad R

alunemanuel Thu, 05/31/2007 - 06:23
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Thank you both for your help on this. I have now got this setup

guruprasadr Wed, 05/30/2007 - 20:49
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HI, [PLS Rate if Helps]


To enable notification of interface, subinterface, and Frame Relay data link connection identifier (DLCI) data link status changes, use the logging event command in interface configuration mode.


Syntax:

logging event {dlci-status-change | link-status | subif-link-status}


PLS Rate if Helps


Best Regards,


Guru Prasad R


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