Router Access

Working with a Cisco Router
On a Cisco router you may have to log in to set up SNMP access.  Since Cisco IOS 12.0 complies with SNMPv2c.  You will need to set the community string, note this is set to read only(ro) and you will need to allow specific IP Addresses to access the router.  One of the biggest problems using SNMP is that ofter the security on the router, especially when using SNMP v3, will not allow access to the information that you want the Nagios server to access.

Lesson 3 | Lesson 5

On a Cisco router you will have to run “show config” and part of the information will be the public string, here is an example.

snmp-server community public RO


Note that the community string is public and that it is read only(RO).

If you need to login to the Cisco router here is the process from a Linux box using minicom.  Need help with minicom?

minicom com1

config t

Router(config)#int e0
Router(config)#snmp-server community public ro                                                                                                  
Router(config)#access-list 60 permit 192.168.5.50                                                                                               
Router(config)#access-list 60 permit 192.168.5.103
Router(config)#no shut


You must have a UDP port, thus an IP address set on the box so that you can set up snmp and the access list.