In ”An introduction to SNMP” I have explained how SNMP protocol works and how use it; but what are the softwares that use SNMP to monitor network bandwith? HP Openview, Ciscoworks, MRTG are some examples. In this article I will explain how monitor Cisco Switches/Routers bandwith under a Linux machine using a free open source tool: MRTG. The Multi Router Traffic Grapher (MRTG) is a tool to monitor the traffic load on network links. MRTG generates HTML pages containing PNG images which provide a LIVE visual representation of this traffic. MRTG consists of a Perl script which uses SNMP to read the traffic counters [...]

In the era of electronic exchanges, tiny spikes and bottlenecks in network traffic can create delays which compromise the split-second accuracy needed for effective trading. Tracking down these problems has been beyond the reach of any technology-until now, thanks to Cisco Systems, Inc. While traditional network monitoring systems can only analyze traffic behavior over a minimum of five minutes or so on average, the Cisco Bandwidth Quality Manager (BQM), part of the Cisco Network Application Performance Analysis (NAPA) Solution, can get down to millisecond level.

Usually when we admin a network, we need to know what are the protocols used more frequently, and why not, discover if someone are using improper P2P software; so we can use SPAN. The Switched Port Analyzer (SPAN) feature, which is sometimes called port mirroring or port monitoring, selects network traffic for analysis by a network analyzer. For example, if you want to capture Ethernet traffic that is sent between host A and host B, you must implement SPAN feature. In this diagram, the sniffer is attached to a port (destination SPAN port) that is configured to receive a copy of [...]

In a network environment, it is a good practice monitor Cisco devices. One of the most famous protocol to control and manage Cisco devices is SNMP (Simple Network Management Protocol). SNMP exposes management data in the form of variables on the managed systems, which describe the system configuration. These variables can then be queried (and sometimes set) by managing applications. The main features are: The SNMP is an application layer protocol that facilitates the exchange of management information between network devices. It is part of the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite. It uses UDP port 161 for the [...]