Track Cisco BGP peers using Nagios

October 31, 2020April 5, 2012 by Stefan Durand

Few will deny that monitoring of Cisco devices is essential part of sysadmin’s job. I personally use Nagios to track states of BGP neighbors on Cisco routers so if one of peers goes down I’ll receive a phone call from Nagios. You may have redundant network topology but it still makes sense to know when peer goes offline, how often it happens and how fast failover router (if any) pick-ups the traffic from failed peer. There are a few plugins for Nagios to monitoring BGP … Read more

Home » Networking » Cisco

Install nfdump and nfsen netflow tools in Linux

October 31, 2020February 23, 2011 by Stefan Durand

Using nfsen it is possible to view IP traffic statistics on Linux interfaces including the graphs showing data sent and received (see the screenshot to the right) as well as historical information about all data transfers. So after you’ve configured nfsen and nfdump to monitor traffic on certain Linux server or router you’ll be able to answer the following example questions: What IP was downloading data through 48161 last Wednesday? or How many bytes were sent to IP 8.8.8.8 via 53 port from Linux server? … Read more

Home » Networking » Cisco

How to monitor traffic at Cisco router using Linux (Netflow)

October 31, 2020November 25, 2010 by Stefan Durand

By default Cisco IOS doesn’t provide any traffic monitoring tools like iftop or iptraff available in Linux. While there are lots of proprietary solutions for this purpose including Cisco Netflow Collection, you are free to choose nfdump and nfsen open source software to monitor traffic of one or many Cisco routers and get detailed monitoring data through your Linux command line or as graphs at absolutely no cost. Below is beginner’s guide that helps to quickly deploy netflow collector and visualizer under Linux and impress … Read more