Technical: How much time do base configurations save? by Terry Danner, Network Infrastructure Engineer

In the networking world - similar to the systems world, we have base configurations that can save many hours of time. Some things are standard on almost all networking equipment. While syntax may change between vendors, your best practices as a network engineer are your standards and do not change. Some things always need to be configured in order for the network to work correctly or else it will be called a “Not”- work.

Below are examples:

Hostname:

This is the name of the switch that will register on the network. Once this command is entered, the prompt will also change to this name for each level of commands. I.E. ManagedSolution> will be the initial login layer ManagedSolution# would be the enable command level prompt.

SNTP Servers:

SNTP = Simple Network Time Protocol. These settings are configured so that the switch synchs time without an outside reliable source(s). This is very important for troubleshooting issues. If you have a failure at 8:00 a.m. on a server that is more than likely using a reliable time source, you would want to look on the switch or firewall log for the same timestamp. If all systems are synching using SNTP it makes it much easier.

DNS Servers:

DNS = Domain Name Servers. This is how the piece of network equipment resolves IP addresses to common names or common names to IP addresses. This really helps with troubleshooting common network problems.

VLAN Names:

This is really an engineer’s standard but if you are supporting multiple clients and every switch you log into is configured with similar VLAN’s, then you will spend less time learning about the environment and more time fixing it.

IP Helper:

The server may change but it is best to enable it on the switch. Remember the VLAN that the DHCP server sits on will not need to accept DHCP requests and normally a switch will not accept a request without an IP Helper statement.

IP Routing:

This really is for Layer 3 purposes only, but if you plan on using it and configuring it - then turn it on. This is your roadmap showing your computers where to go.

Recommendations:

Take each equipment vendor that you configure and support and build a base configuration that includes the above information in a text file format. One for Cisco, Dell, Foundry, and any other vendors you may support. Remember to include the configure command and the exit commands followed by the exit command or ! to keep the script flowing between groups of interface commands. An example is below:
cConfigure t
interface vlan 4
ip address 10.1.4.1 255.255.255.0
exit
!
interface vlan 8
ip address 10.1.8.1 255.255.255.0
exit
!

By building out a base configuration and executing the script, I have saved countless hours of time configuring the standard settings for switches.

Oh and remember... the most important command to execute before moving on to the next client/customer issue once the switch is configured or the problem is solved is: copy running-config startup-config. This way you won’t be reconfiguring the changes to the environment after the next power outage or reboot of the switch.