Thursday, June 18, 2020

Usefull OIDs when using snmpwalk

When conducting reconnaissance activities to discover the IP address details of public facing network devices which has SNMP enabled, snmpwalk will be a very useful tool.

If you run the below command, it will give you a verbose output with all the available details.
$ snmpwalk -v 2c -c public <IP_Address>

Every piece of information an SNMP Agent serves out, and every type of trap that it supports, is associated with a unique identifier known as an OID (Object Identifier).OID is a system created by the ITU and ISO organizations for international standardization of Data. It isn’t only used for network monitoring or SNMP, it is a standard used for all sorts of data.

If you want specific details, you will have to use specific OIDs. Some of the useful OIDs have been described below in more details.

To discover the remote network device operating system details
$ snmpwalk -v 2c -c public <IP_Address> iso.3.6.1.2.1.47.1.1.1.1.2

To discover the network interface IP addresses
$ snmpwalk -v 2c -c public <IP_Address> iso.3.6.1.2.1.4.20.1.1

To discover the interface names (strings)
$ snmpwalk -v 2c -c public <IP_Address> iso.3.6.1.2.1.31.1.1.1.1.1

To discover more details relating to device identifications
$ snmpwalk -v 2c -c public <IP_Address> iso.3.6.1.2.1.1.4.0

0 comments: