LibreNMS syslog.ibd cleanup

Recently I ran into an issue where a librenms install was taking up a crazy amount of disk space. This was tracked down to the syslog.ibd file . Even thought I had set my options to be less than 10 days per this link https://docs.librenms.org/Support/Cleanup-options/ I still was having a huge file.

Here is what I did to fix it. My root partition was too full to start MariaDB. I went into var and cleaned out enough log files to make space to start MariaDB. The following are tee commands I ran on CentOS 7 to fix it.

mysql -u username -p

Once at an MYSQL prompt after logging in I issued the following command to verify I could see my librenms database.

show databases;

The I issued

use dbname;

In may case it was “librenms”. Once connected to the database I ran the following command

DELETE FROM syslog WHERE timestamp < '2021-1-28 08:00:00';

This commands removes all syslog entries from the database before the date and time specified. In my case this was close to 40 GIG.

After I restarted MariaDB, ran .daily.sh and all was good.

Network troubleshooting tools

Recently, there was a thread on the NANOG list asking what were somne favorite network troubleshooting tools. I have taken many of these tools and created the following list.

http://ping.pe/
Simple pingport and dig commands

https://mtr.sh/
BGP Looking glass

https://perfops.net/mtr-from-world
Traceroute from various hosts on the net

http://www.traceroute6.net/
IPV6 tools (ping,traceroute,etc)

https://dnsviz.net/
Carious DNS tools

http://irrexplorer.nlnog.net/
Routing Registry object explorer

https://mxtoolbox.com/
DNS and Mail tools

Frequently Asked Questions On OTDRS

https://www.thefoa.org/tech/ref/testing/OTDR/OTDR-FAQS.html?fbclid=IwAR1wWEr5qG0h4r2vBsnEEmCWrT20VYIWGCnseOD2_MChJiaL6PX9RaCm1ow

Frequently Asked Questions On OTDRS And Hints On Their Use

OTDRs, also known by their technical name optical time domain reflectometers, are valuable fiber optic testers when used properly, but improper use can be misleading and, in our experience, lead to expensive mistakes for the contractor. We have been personally involved in several instances where misapplication of OTDR testing has cost the contractor as much as $100,000 in wasted time and materials. Needless to say, it’s extremely important to understand how to use these instruments correctly.

A little reboot now and then..

Just a reminder that rebooting does help. My home network was experiencing slowness and lag.  Xbox games were having issues, etc.  Started pings to various sites and they all looked this way. Even to the provider’s DNS.  I rebooted the CPE and all is well.  Sometimes it’s the simple things.

Before the reboot

After the reboot

MTR Traceroute and you

For those of you who don’t know about MTR traceroute it can be a very helpful diagnostic tool.  MTR is a visual application that combines the functionality of the traceroute and ping in a single network diagnostic tool.

https://www.bitwizard.nl/mtr/

If you are a Mac user like me MTR is available through homebrew.
http://macappstore.org/mtr/

mtr to j2sw.com from my comcast connection.

Windows Users
https://sourceforge.net/projects/winmtr/

 

Troubleshooting a fiber optic link on Cisco switches

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Podcast: Quick troubleshooting for ISP networks

Been a little bit so I wanted to do a short talk about troubleshooting in ISP networks. I see too many folks waste a lot of time when they should be starting qt the lower levels of the OSI model and working up.