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Can anyone explain to me what SNMP is used for in a home Desktop Ubuntu install?

Is it needed? There is no network of any kind other than the cable modem.

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    Do you have snmp installed on your Ubuntu desktop by default? Could you be more specific?
    – Huygens
    May 24, 2012 at 9:47

5 Answers 5

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What is SNMP?

SNMP(Simple Network Management Protocol) "is a widely used protocol for monitoring the health and welfare of network equipment (eg. routers), computer equipment and even devices like UPSs.".

It is commonly used by network and system administrators to gather operational statistics(such as measuring network bandwidth traffic, cpu usage, or available hard drive space) as well as setting system parameters.

What does this mean for the average desktop user?

As the question currently stands, SNMP is of little, or no, interest to the casual desktop user.

By default, in Ubuntu, the basic SNMP files (/etc/snmp/snmp.conf for example) are installed. But, they are not enabled, not used at all, and have little significance as far as system security is concerned.

Why would I want to enable and use SNMP?

As very simple use case for a more advanced(or curious) user would be to set up a monitoring/graphing system like MRTG, Cacti, or Nagios to keep an eye on the health of their systems and network. There are a number of useful questions on this site that go into details on configuring applications that require the use of SNMP.

This question is a good starting point to look at some of the many applications that employ SNMP to gather system and network data.

How do I enable SNMP on my system?

See my answer here.

  1. Edit the file /etc/snmp/snmp.conf and comment out the line containing "mibs:"
  2. Next, assuming you haven't done this already, you will need to obtain the full set of IETF MIBs. These files do not ship, by default, on Debian/Ubuntu systems due to licensing issues.

    • From the console (Ctrl-Alt-t), enter the following commands:

    • sudo apt-get install snmp-mibs-downloader

    • sudo download-mibs

  3. You should be able to test this configuration by running the following command:

    • snmpwalk -v 2c -c public <InsertYourIPAddressHere> system
    • If working properly, you should get a response similar to the following:

    SNMPv2-MIB::sysDescr.0 = STRING: Linux foucault 3.2.0-38-generic-pae #59-Ubuntu SMP Tue Feb 5 18:16:32 UTC 2013 i686

Where can I learn more about SNMP?

Net-SNMP is the "canonical" package for most installations.

A good introduction can be found here.

Finally, the wikipedia entry for SNMP.

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  • If my test with smtpwalk doesnt return anything close to what you posted, how can I troubleshoot this? Im trying to get nagios up and running and need to install and test snmp first Feb 23, 2013 at 4:57
  • @ProfessionalAmateur I suggest starting a new question. Be sure to detail what you have troubleshot before, what error messages you may have gotten, etc... Feb 23, 2013 at 6:52
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                                                 What Is SNMP?

Simple Network Management Protocol (SNMP) 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 network-attached devices for conditions that warrant administrative attention. SNMP is a component of the Internet Protocol Suite as defined by the Internet Engineering Task Force (IETF). It consists of a set of standards for network management, including an application layer protocol, a database schema, and a set of data objects. (For more detail )

TechNet SNMP                 PulseWan

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By default SNMP (the agent or monitored device) is not installed on Ubuntu Desktop.

Only the SNMP library is installed as it can be used to get the state of a network printer for instance but it is not activated unless the printer driver requests it.

Overall SNMP (the agent or monitored device) has not much use on a Home Desktop, as you suspected it.

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SNMP is used to remotely monitor a system. It can also be used to remotely configure a system, if the daemon allows write access, which is rare. You don't need it if you aren't doing fine-grained analysis of your system state, or central monitoring or configuration management. (Even without it, a program like Nagios can check to see if a system is up, whether HTTP or SSH services are listening on ports, etc..)

Sometimes it appears as if SNMP libraries or functionality are piggybacking on the installation of other programs, but in reality, unless they touch /etc/snmp/snmpd.conf, you've mis-read the purpose of the files. For instance, CUPS seems to include an SNMP configuration file, but its purpose is to allow CUPS to find printers on other systems that expose them via SNMP.

If you block UDP on port 161 or restrict the listener to localhost (127.0.0.1 and ::1/128), this will prevent remote querying of your system's information via SNMP.

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  • The SNMP configuration file in CUPS is there to configure how CUPS itself discovers printers via SNMP, not to provide information on CUPS via SNMP. For example: Monitoring CUPS- part2 May 25, 2016 at 14:58
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    @AndrewBeals Thanks for the info -- didn't know that ; feel free to edit my answer.
    – belacqua
    May 25, 2016 at 15:13
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http://myhowtosandprojects.blogspot.it/2009/04/what-is-net-snmp-simple-network.html

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  • @jasmines It looks like this answer now contains the entire contents of that page, copied word-for-word. Is there a copyright notice somewhere (or perhaps permission you've yourself asked for and received?) allow this? It's best to include information instead of just a link, but large amounts of text should not be copied directly into an answer unless the content licensed or otherwise offered in a way that allows it to be distributed under cc-wiki. Oct 5, 2012 at 1:35
  • It also doesn't really answer the question as written.
    – OrangeDog
    Jan 21, 2013 at 13:51
  • @jasmines - your edited in information basically copied from the blog - this doesnt appear to be fair use and hence could be construed as breaching any copyright on the blog. I have rolled this back. Please rework your answer in your own words and with your own example commands etc.
    – fossfreedom
    Feb 7, 2013 at 22:43

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