You want to record important information, such as physical locations, contact names, and serial numbers for later SNMP access.
To record important physical information regarding the router, use the following commands:
Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#snmp-server contact Ian Brown 416-555-2943 Router(config)#snmp-server location 999 Queen St. W., Toronto, Ont. Router(config)#snmp-server chassis-id JAX123456789 Router(config)#end Router#
It is an extremely good network management practice to add useful information such as contact names, router locations, and serial numbers directly into the router configuration. This information can be extracted later using snmpget requests, either directly or invoked from scripts that make output easier to understand. This is true not only for Cisco routers, of course. Any time you have to manage remote equipment, you should configure important information like serial numbers and locations so that you can read it with SNMP. When a field technician swaps or moves a piece of equipment, they can update this information. So this way you can easily verify the information you store in your central equipment inventory database.
When you save the contact name, router location, and serial number in the router configuration like this, it is also easy to extract from the command line and configuration files as well:
Router#show snmp Chassis: JAX123456789 Contact: Ian Brown 416-555-2943 Location: 999 Queen St. W., Toronto, Ontario 417 SNMP packets input 0 Bad SNMP version errors 141 Unknown community name 3 Illegal operation for community name supplied 0 Encoding errors 224 Number of requested variables 49 Number of altered variables 224 Get-request PDUs 0 Get-next PDUs 52 Set-request PDUs 299 SNMP packets output 0 Too big errors (Maximum packet size 1500) 3 No such name errors 0 Bad values errors 0 General errors 276 Response PDUs 23 Trap PDUs SNMP logging: enabled Logging to 172.25.1.1.162, 0/10, 21 sent, 2 dropped. Router#
You can also extract individual pieces of information by using the following commands:
Router#show snmp contact Ian Brown 416-555-2943 Router#show snmp location 999 Queen St. W., Toronto, Ontario Router#show snmp chassis JAX123456789 Router#
It is also useful to extract this information from a backup of the router's configuration file. It is a good network management practice to keep a backup copy of every router's configuration on a central server such as the NMS. Then you can extract vital information like the router's serial number. You will often need this information for service and support when a device fails. Of course, when a device fails, you can't reach it through SNMP, so it can be invaluable to be able to get this information from the backup configuration file. On a Unix server, you can use the grep utility to easily extract the required information:
Freebsd% grep snmp-server Router.confg snmp-server community ORARO RO snmp-server community ORARW RW snmp-server location 999 Queen St. W., Toronto, Ontario snmp-server contact Ian Brown 416-555-2943 snmp-server chassis-id JAX123456789 snmp-server host 172.25.1.1 ORATRAP Freebsd%
If the router is reachable, you can also extract this information via SNMP:
Freebsd% snmpget v1 -c ORARO Router .184.108.40.206.220.127.116.11.0 system.sysLocation.0 = 999 Queen St. W., Toronto, Ontario Freebsd% snmpget v1 -c ORARO Router .18.104.22.168.22.214.171.124.0 system.sysContact.0 = Ian Brown 416-555-2943 Freebsd% snmpget v1 -c ORARO Router .126.96.36.199.188.8.131.52.6.3.0 enterprises.184.108.40.206.0 = "JAX123456789" Freebsd%
Recipe 17.5 uses this information to construct a summary inventory report for all of the routers in a network.
Router Configuration and File Management
User Access and Privilege Levels
Handling Queuing and Congestion
Tunnels and VPNs
NTP and Time
Router Interfaces and Media
Simple Network Management Protocol
First Hop Redundancy Protocols
Appendix 1. External Software Packages
Appendix 2. IP Precedence, TOS, and DSCP Classifications