How SNMP Works - a quick guide
Summary
TLDRThis video provides a concise introduction to SNMP (Simple Network Management Protocol), covering its basics to help you start monitoring devices. It explains key terms like OIDs (Object Identifiers) and MIBs (Management Information Bases), and how SNMP works in practice, including polling and notifying methods. The video also discusses the different SNMP versions, highlighting the security advantages of version 3 over versions 1 and 2c. By the end, you'll understand how to use SNMP for monitoring network devices such as switches, routers, and servers.
Takeaways
- 📘 SNMP stands for Simple Network Management Protocol, introduced in 1988.
- 🔍 SNMP is used to monitor and modify settings on network equipment like switches, routers, and other devices.
- 🔑 Key terms to know: OID (Object Identifier) and MIB (Management Information Base).
- 🌡️ OIDs are unique identifiers for specific parameters on devices, such as temperature sensors.
- 📜 MIBs are text files that translate numerical OIDs into understandable names.
- 🖥️ Standard OIDs and MIBs are often built into SNMP implementations for basic monitoring.
- 🔄 SNMP can be used in two ways: polling (querying devices) and notifying (devices sending alerts).
- 🔐 There are three versions of SNMP: v1, v2c, and v3, with v3 being the most secure.
- 🛡️ Version 3 enhances security by requiring usernames, passwords, and offering encryption.
- ⚙️ Best practice is to use SNMP v3 whenever possible, although v2c is still commonly used.
Q & A
What does SNMP stand for?
-SNMP stands for Simple Network Management Protocol.
Since when has SNMP been in use?
-SNMP has been in use since 1988.
What was the initial purpose of SNMP?
-SNMP was initially developed to allow administrators to monitor networking equipment's current state and remotely modify settings and configurations on the equipment.
What are the two key terms introduced in the script related to SNMP?
-The two key terms introduced are OID (Object Identifier) and MIB (Management Information Base).
What is an OID in the context of SNMP?
-An OID is a numerical identifier used to represent anything and everything on a device that can be monitored with SNMP.
What is a MIB and why is it used?
-A MIB is a text file that allows us to translate numerical OIDs into more understandable names, making it easier to identify what is being monitored.
Why are MIBs considered helpful in SNMP monitoring?
-MIBs are helpful because they simplify the process of identifying and monitoring various parameters on a device by translating numerical OIDs into more comprehensible names.
What are the two primary methods by which SNMP can be used to monitor devices?
-The two primary methods are polling, where the network monitoring system requests information from the device, and notifying, where the device sends information to the monitoring system.
What is the main difference between SNMP versions 1 and 2c and version 3 in terms of security?
-Version 3 is more secure than versions 1 and 2c because it requires a username and password and offers encryption, whereas versions 1 and 2c only require a community string and do not offer encryption.
Why might some administrators still use SNMP version 2c despite the availability of version 3?
-Some administrators might still use SNMP version 2c because not all devices and operating systems support version 3, and it is often still considered sufficient for their needs.
What is the recommended best practice regarding the use of SNMP versions?
-The best practice is to use SNMP version 3 whenever possible due to its enhanced security features.
Where can one find information about OIDs and MIBs for specific devices?
-Information about OIDs and MIBs for specific devices can typically be found in the product manuals from the manufacturer, which are often available online.
Outlines
🔍 Introduction to SNMP Explainer
This introductory paragraph sets the stage for an SNMP explainer video. The speaker promises to teach the basics of SNMP for device monitoring, emphasizing simplicity and avoiding unnecessary complexity. SNMP, or Simple Network Management Protocol, has been in use since 1988 and is designed for monitoring and remotely modifying network equipment. The script mentions that SNMP is not limited to switches and routers but can also be used for a variety of devices, including Windows and Linux machines, printers, and UPS systems. Two key terms, OID (Object Identifier) and MIB (Management Information Base), are introduced as essential concepts for understanding SNMP.
📚 Understanding SNMP Operations and Security
The second paragraph delves into the practical use of SNMP, explaining how it operates in daily practice through polling and notifications. Polling involves the monitoring system requesting information from a device, while notifications allow devices to send unsolicited messages about certain OIDs. The paragraph also discusses the evolution of SNMP versions, highlighting the security improvements in SNMP version 3, which includes authentication and encryption not present in versions 1 and 2c. The speaker advises using SNMP version 3 whenever possible for enhanced security, but acknowledges that not all devices support it. The video concludes by encouraging viewers to start monitoring with SNMP and provides a link to download Nagios XI for monitoring purposes.
Mindmap
Keywords
💡SNMP
💡OID
💡MIB
💡Nagios
💡Polling
💡Notifying
💡Community String
💡Version 3
💡Traps
💡Encryption
Highlights
Introduction to SNMP (Simple Network Management Protocol) and its purpose.
SNMP has been around since 1988 and is used to monitor and manage network devices.
SNMP can monitor a variety of devices including switches, routers, Windows and Linux machines, printers, and UPS systems.
Key terms: OID (Object Identifier) and MIB (Management Information Base).
OID is like an IP address for values to monitor, such as device temperature.
MIB is a text file that translates numerical OIDs into readable text-based OIDs.
Standard OIDs and MIBs are incorporated into most SNMP implementations by default.
Basic device information like uptime can be monitored without needing specific OIDs or MIBs.
For non-standard monitoring, product manuals from manufacturers often provide necessary OIDs and MIBs.
Two ways to use SNMP: polling and notifying.
Polling involves the network monitoring system requesting information from a device.
Notifying involves the device sending information to the network monitoring system.
Three versions of SNMP: version 1, version 2c, and version 3, with version 3 being the most secure.
Version 3 requires a username and password and offers encryption.
Despite its security advantages, not all devices support SNMP version 3.
It is best practice to use SNMP version 3 whenever possible.
Summary: Understanding OIDs, MIBs, polling, traps, and SNMP versions prepares you to start monitoring with SNMP.
Download Nagios XI for practical SNMP monitoring.
Transcripts
[Music]
hey everybody welcome to this SNMP
explainer in just a couple of minutes
I'm gonna teach you enough about SNMP to
be able to start monitoring devices
while SNMP is a little complex there's a
lot you don't need to know just to start
monitoring so we're gonna focus on the
absolute basics here and I promise I
won't get you lost in unnecessary
details how are we gonna do that
well we're gonna talk about some basic
background information we're gonna talk
about two key terms you need to know
we're gonna talk about why switches and
routers are simple to monitor we're
gonna talk about how SNMP works on a
practical level and we're gonna talk
about the different versions of SNMP are
you ready let's get started
SNMP stands for simple network
management protocol it's been around
since 1988 so it's pretty well used SNMP
was developed to allow administrators to
both monitor networking equipments
current state and also remotely modify
settings and configurations on the
equipment while SNMP was initially
developed for switchers and routers it
has since been extended to a wide array
of other devices such as Windows and
Linux machines printers and
uninterruptible power supplies among
many many other things there are two key
terms you need to know ID and mim o it
is short for object identifier think of
it like this anything and everything on
a device that can't be monitored with
SNMP has annoyed for example say I want
to monitor the temperature on a network
attached storage device we have here
Nagios the oil for the temperature
sensor on the device is a bunch of
numbers separated by dots that number
might look confusing but all you really
have to know is each thing we can
monitor like device temperature has
annoyed you might think of annoyed as
something similar to an IP address for a
value we use an application like Nagios
X I to ask the device what the value of
any particular I'd have to be mint is
short for management information base
that sounds a lot more complicated than
it actually is am it is a text file that
allows us to translate numerical oils
into
bass toys so instead of using the
numerical oi for the temperature sensor
in our example we can use this word
based oil which makes it a lot easier to
understand what we're monitoring now
technically you don't have to use MIBs
at all you could always use only
numerical hoids but MIBs can make your
life a lot easier there are a number of
standard Lloyd's and MIBs that are
incorporated into most SNMP
implementations by default for example
on almost any system out there you
should be able to ask the uptime of a
device with the oeid cysts uptime zero
this is great because when you go to do
basic switch or router monitoring in
Nagios x.i you don't need to know a
single weight or find any mips because
those are already built in you really
only need to figure out ways and MIPS
when you have a non-standard
to monitor like the temperature sensor
on a network attached storage device
like we just talked about a minute ago
how do you find out what the oeid are
and where do you find MIPS the best
place to start on both of those
questions will be the product manuals
from the manufacturer of the device many
times these documents are available
online and a simple search will get you
the information you need so here is how
SNMP gets used in day-to-day practice
you have a network monitoring system
like Nagios this is what monitors the
things you want to monitor and then you
have the things you want to monitor like
switches and routers and servers and
uninterruptible power supplies there are
two ways to use SNMP the first way is
called polling with polling the network
monitoring system connects to the
monitored device on port 161 and tells
the device which ID it wants information
on the device then responds with the
information to the network monitoring
systems port 161 in the second way we do
what's called notifying with notifying
the device simply sends a message about
a noid to the network monitoring systems
port 162 these messages are variously
called either traps notifications or
informs there are three versions of the
SNMP protocol version 1 version 2c and
version 3 the biggest difference for our
purposes is that version 3 is more
secure than versions 1
to see in two ways first four versions
one and two see you don't even have to
supply a username all you need is a
special password called the community
string version three gets rid of the
community string and makes admins
specify a username and a password
second versions one and two C don't
offer encryption but version 3 does keep
in mind that SNMP can be used to change
device settings so if an attacker were
able to intercept and read your
unencrypted v1 or v2 C SNMP packets the
attacker could take control of the
device you might find out there that
SNMP version 2 C is still pretty
commonly used why wouldn't everyone
always use version 3 well quite simply
for a number of reasons not all devices
and operating systems support version 3
it is best practice however to use
version 3 whenever possible you now know
enough to be dangerous you know about
Lloyd's and MIPS you know about the two
ways to use that cmp to monitor that
would be polling and traps
you know switches and routers are easy
to monitor and you know about SNMP
versions you know enough to get out
there and start monitoring with SNMP
thanks for watching download Nagios exei
from the link in the description below
and you'll be monitoring in no time
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