Network monitoring
Encyclopedia
The term network monitoring describes the use of a system that constantly monitors a computer network
for slow or failing components and that notifies the network administrator
(via email, pager or other alarms) in case of outages. It is a subset of the functions involved in network management
.
For example, to determine the status of a webserver, monitoring software may periodically send an HTTP
request to fetch a page. For email
servers, a test message might be sent through SMTP
and retrieved by IMAP
or POP3
.
Commonly measured metrics are response time, availability
and uptime
, although both consistency and reliability metrics are starting to gain popularity. The widespread addition of WAN optimization
devices is having an adverse effect on most network monitoring tools -- especially when it comes to measuring accurate end-to-end response time because they limit round trip visibility.
Status request failures - such as when a connection cannot be established, it times-out
, or the document or message cannot be retrieved - usually produce an action from the monitoring system. These actions vary -- an alarm may be sent (via SMS
, email, etc.) to the resident sysadmin, automatic failover systems may be activated to remove the troubled server from duty until it can be repaired, etc.
Monitoring the performance of a network uplink
is also known as network traffic measurement
, and more software is listed there.
is an important area of network measurement, which deals with monitoring the health of various links in a network using end-to-end probes sent by agents located at vantage points in the network/Internet.
is another important area of network measurement. It includes
the methods, systems, algorithms and tools to monitor the routing posture of networks. Incorrect routing or routing issues cause undesirable performance degradation or downtime.
service can check HTTP
pages, HTTPS
, SNMP
, FTP
, SMTP
, POP3
, IMAP
, DNS
, SSH
, TELNET
, SSL, TCP
, ICMP
, SIP
, UDP
, Media Streaming and a range of other ports with a variety of check intervals ranging from every four hours to every one minute. Typically, most network monitoring services test your server anywhere between once-per-hour to once-per-minute.
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
for slow or failing components and that notifies the network administrator
Network administrator
A network administrator, network analyst or network engineer is a person responsible for the maintenance of computer hardware and software that comprises a computer network...
(via email, pager or other alarms) in case of outages. It is a subset of the functions involved in network management
Network management
Network management refers to the activities, methods, procedures, and tools that pertain to the operation, administration, maintenance, and provisioning of networked systems....
.
Details
While an intrusion detection system monitors a network for threats from the outside, a network monitoring system monitors the network for problems caused by overloaded and/or crashed servers, network connections or other devices.For example, to determine the status of a webserver, monitoring software may periodically send an HTTP
Hypertext Transfer Protocol
The Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....
request to fetch a page. For email
Email
Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
servers, a test message might be sent through SMTP
Simple Mail Transfer Protocol
Simple Mail Transfer Protocol is an Internet standard for electronic mail transmission across Internet Protocol networks. SMTP was first defined by RFC 821 , and last updated by RFC 5321 which includes the extended SMTP additions, and is the protocol in widespread use today...
and retrieved by IMAP
Internet Message Access Protocol
Internet message access protocol is one of the two most prevalent Internet standard protocols for e-mail retrieval, the other being the Post Office Protocol...
or POP3
Post Office Protocol
In computing, the Post Office Protocol is an application-layer Internet standard protocol used by local e-mail clients to retrieve e-mail from a remote server over a TCP/IP connection. POP and IMAP are the two most prevalent Internet standard protocols for e-mail retrieval. Virtually all modern...
.
Commonly measured metrics are response time, availability
Availability
In telecommunications and reliability theory, the term availability has the following meanings:* The degree to which a system, subsystem, or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e., a random, time...
and uptime
Uptime
Uptime is a measure of the time a machine has been up without any downtime.It is often used as a measure of computer operating system reliability or stability, in that this time represents the time a computer can be left unattended without crashing, or needing to be rebooted for administrative or...
, although both consistency and reliability metrics are starting to gain popularity. The widespread addition of WAN optimization
WAN Optimization
WAN optimization is a collection of techniques for increasing data-transfer efficiencies across wide-area networks. In 2008, the WAN optimization market was estimated to be $1 billion , and it will grow to $4.4 billion according to Gartner, a technology research firm.The most common measures of...
devices is having an adverse effect on most network monitoring tools -- especially when it comes to measuring accurate end-to-end response time because they limit round trip visibility.
Status request failures - such as when a connection cannot be established, it times-out
Timeout (telecommunication)
In telecommunication and related engineering , the term timeout or time-out has several meanings, including...
, or the document or message cannot be retrieved - usually produce an action from the monitoring system. These actions vary -- an alarm may be sent (via SMS
SMS
SMS is a form of text messaging communication on phones and mobile phones. The terms SMS or sms may also refer to:- Computer hardware :...
, email, etc.) to the resident sysadmin, automatic failover systems may be activated to remove the troubled server from duty until it can be repaired, etc.
Monitoring the performance of a network uplink
Uplink
A telecommunications link is generally one of several types of information transmission paths such as those provided by communication satellites to connect two points on earth.-Uplink:...
is also known as network traffic measurement
Network traffic measurement
In computer networks, network traffic measurement is the process of measuring the amount and type of traffic on a particular network. This is especially important with regard to effective bandwidth management.- Tools :...
, and more software is listed there.
Network tomography
Network tomographyNetwork tomography
Network tomography is the study of a network's internal characteristics using information derived from end point data. The word tomography is used to link the field, in concept, to other processes that infer the internal characteristics of an object from external observation, as is done in magnetic...
is an important area of network measurement, which deals with monitoring the health of various links in a network using end-to-end probes sent by agents located at vantage points in the network/Internet.
Route analytics
Route analyticsRoute analytics
Route analytics is an emerging network monitoring technology specifically developed to analyze the routing protocols and structures in meshed IP Networks...
is another important area of network measurement. It includes
the methods, systems, algorithms and tools to monitor the routing posture of networks. Incorrect routing or routing issues cause undesirable performance degradation or downtime.
Various types of protocols
Website monitoringWebsite monitoring
Website monitoring is the process of testing and verifying that end-users can interact with a website or web application. Website monitoring is often used by businesses to ensure that their sites are live and responding....
service can check HTTP
Hypertext Transfer Protocol
The Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....
pages, HTTPS
Https
Hypertext Transfer Protocol Secure is a combination of the Hypertext Transfer Protocol with SSL/TLS protocol to provide encrypted communication and secure identification of a network web server...
, SNMP
Simple Network Management Protocol
Simple Network Management Protocol is an "Internet-standard protocol for managing devices on IP networks. Devices that typically support SNMP include routers, switches, servers, workstations, printers, modem racks, and more." It is used mostly in network management systems to monitor...
, FTP
File Transfer Protocol
File Transfer Protocol is a standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server...
, SMTP
Simple Mail Transfer Protocol
Simple Mail Transfer Protocol is an Internet standard for electronic mail transmission across Internet Protocol networks. SMTP was first defined by RFC 821 , and last updated by RFC 5321 which includes the extended SMTP additions, and is the protocol in widespread use today...
, POP3
Post Office Protocol
In computing, the Post Office Protocol is an application-layer Internet standard protocol used by local e-mail clients to retrieve e-mail from a remote server over a TCP/IP connection. POP and IMAP are the two most prevalent Internet standard protocols for e-mail retrieval. Virtually all modern...
, IMAP
Internet Message Access Protocol
Internet message access protocol is one of the two most prevalent Internet standard protocols for e-mail retrieval, the other being the Post Office Protocol...
, DNS
Domain name system
The Domain Name System is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities...
, SSH
Secure Shell
Secure Shell is a network protocol for secure data communication, remote shell services or command execution and other secure network services between two networked computers that it connects via a secure channel over an insecure network: a server and a client...
, TELNET
TELNET
Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection...
, SSL, TCP
Transmission Control Protocol
The Transmission Control Protocol is one of the core protocols of the Internet Protocol Suite. TCP is one of the two original components of the suite, complementing the Internet Protocol , and therefore the entire suite is commonly referred to as TCP/IP...
, ICMP
Internet Control Message Protocol
The Internet Control Message Protocol is one of the core protocols of the Internet Protocol Suite. It is chiefly used by the operating systems of networked computers to send error messages indicating, for example, that a requested service is not available or that a host or router could not be...
, SIP
Session Initiation Protocol
The Session Initiation Protocol is an IETF-defined signaling protocol widely used for controlling communication sessions such as voice and video calls over Internet Protocol . The protocol can be used for creating, modifying and terminating two-party or multiparty sessions...
, UDP
User Datagram Protocol
The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...
, Media Streaming and a range of other ports with a variety of check intervals ranging from every four hours to every one minute. Typically, most network monitoring services test your server anywhere between once-per-hour to once-per-minute.
Servers around the globe
Network monitoring services usually have a number of servers around the globe - for example in America, Europe, Asia, Australia and other locations. By having multiple servers in different geographic locations, a monitoring service can determine if a Web server is available across different networks worldwide. The more the locations used, the more complete is the picture on network availability.Notable Network Monitoring Software
- AccelopsAccelopsAccelOps provides integrated datacenter monitoring and Business Service Management software delivered as a Virtual Appliance or Software-as-a-Service .-Overview:...
- AggreGate Network ManagerAggreGate PlatformAggreGate Device Management Platform is a software framework used for monitoring and managing diverse hardware devices. Though often used in OEM projects, AggreGate offers several out-of-box solutions in areas such as network management, industrial and building automation, physical access control,...
- CapsaCapsaCapsa is the name for a family of packet analyzer developed by Colasoft for network administrators to monitor, troubleshoot and analysis wired & wireless networks...
- CimTrakCimTrakCimTrak is a commercially available File integrity monitoring and Regulatory compliance Auditing software solution. CimTrak assists in ensuring the availability and integrity of critical IT assets by instantly detecting the root-cause and responding immediately to any unexpected changes to the...
Integrity & Compliance Suite - IcingaIcingaIcinga is an open source network and computer system monitoring application. It was originally created as a fork of the Nagios system monitoring application in 2009....
- InterMapperInterMapperInterMapper is a cross-platform network monitoring program distributed by Dartware, LLC. The current version of InterMapper is written in Java, and comes with a variety of network probes based on ping, SNMP, [] and other network protocols used to monitor the state of networked devices and servers....
- Microsoft Network Monitor
- NagiosNagiosNagios is a popular open source computer system and network monitoring software application. It watches hosts and services, alerting users when things go wrong and again when they get better....
- OpenNMSOpenNMSOpenNMS is an enterprise grade network monitoring and network management platform developed under the free software or open source model. It consists of a community supported, free software project as well as a corporation, The OpenNMS Group, offering commercial services, training and support.The...
- OpsviewOpsviewOpsview is an open source network, server and application monitoring tool. It is released under the GNU General Public License version 2....
- PRTG Network Monitor
- ShinkenShinken (software)Shinken is an open source computer system and network monitoring software application compatible with Nagios. It watches hosts and services, alerting users when things go wrong and again when they get better. The major improvement of Shinken over Nagios is the availability to have a load balanced...
- WiresharkWiresharkWireshark is a free and open-source packet analyzer. It is used for network troubleshooting, analysis, software and communications protocol development, and education...
- XymonXymonThis network monitoring software has its roots in another piece of network monitoring software called BIG BROTHER SYSTEM AND NETWORK MONITOR . Between 2002 and 2004, an open source add-on called bbgen toolkit was created by Henrik Storner, then in March 2005 a stand-alone version was released...
- ZabbixZabbixZabbix is a network management system created by Alexei Vladishev. It is designed to monitor and track the status of various network services, servers, and other network hardware....
- Zyrion TraverseZyrion TraverseZyrion Traverse is a IT Infrastructure & Cloud monitoring software that leverages the concept of Business Service Management using ‘service containers’ for correlating application and network problems. BSM has gained prevalence in the network management arena in recent years...
See also
- Comparison of network monitoring systemsComparison of network monitoring systemsThis is a comparison of some notable network monitoring systems.- Legend :Product Name : The name of the software, linked to its Wikipedia article...
- Myth of the nines
- Network Monitoring Interface CardNetwork Monitoring Interface CardA network monitoring interface card or NMIC is similar to a network card . However, unlike a standard network card, an NMIC is designed to passively listen on a network. At a functional level, an NMIC may differ from a NIC, in that the NMIC may not have a MAC Address, may lack the ability to...
- Network tapNetwork tapA network tap is a hardware device which provides a way to access the data flowing across a computer network. In many cases, it is desirable for a third party to monitor the traffic between two points in the network. If the network between points A and B consists of a physical cable, a "network...
- Business service managementBusiness Service ManagementBusiness service management is an approach used to manage business-aligned IT services. A BSM philosophy promotes a customer-centric and business-focused approach to Service Management, aligning business objectives and priorities with IT or ICT from strategy through to operations and continual...