You have a 100 routers in your network. For simplicity let’s say the gear is all Cisco and running the same version of iOS. If each router serves as a gateway to the others, sucessfully ferrying packets among many edge nodes distributed throughout the various subnets, your routing table already covers all the relevant route permutations.


Today you need to turn-up a new subnet on the network. Besides readying the new device(s), you need to modify the routing table on all other routers to include a new route.


A TFTP server would help only if all devices targeted could download the same config file. In this case, each ip route statement will be a little different for each device.


Do you have the time to login on each router to update the table? You might—if you devote the entire day to this numbing task.


Automating Trivial Configuration Changes

Essentially, you need a scripting tool that supports octet replacements based on a defined pattern; which is what version 7.1 of SolarWinds Network Configuration Manager offers with the new function called setoctet—available in creating Change Config Templates.


With this function you can create a script to perform programmatic substitutions for a specific octet in an IP address, so that the value of the next hop gateway to the new route statement—ip route {network}{mask}{gateway}—can be appropriately altered.


A web-based template fronts this script and allows you or a member of your team to input the range of devices for which you want to target the change. For each targeted device the output is a specific set of CLI command statements. You confirm that the CLI statements include the ip route statement that will update the routing table for the appropriately targeted device. When you have verified the matches (CLI statements/device) you click a button to schedule all the necessary jobs that accomplish the routing table update across the devices targeted for the change.


For detailed information on creating and using Config Change Templates in NCM see this chapter of the NCM administrator guide. To explore the workflow of the Config Change Template feature see this live demo.