Chapter 9. Configuration Management
In addition to the normal operations such as
copy run start, and the like, the running configuration in Arista’s Extensible Operating System (EOS) can be managed in a variety of interesting ways. To understand the majority of them, I’d like to begin with the command
Remember that Arista EOS, much like the industry standard CLI, is additive. In other words, if you want to remove a command from the running configuration, you must add a command to negate the existing command. For example, if I have a switch that has the following configuration
Arista(config-if-Et1)#sho active interface Ethernet1 no switchport ip address 10.10.10.1/24
to remove the IP address, I must add a command to do so:
Arista(config-if-Et1)#no ip address Arista(config-if-Et1)#sho active interface Ethernet1 no switchport
Given this model, for decades the only way to load a completely new configuration on a device was either to carefully negate every existing command (a practical impossibility in most cases, not to mention a recipe for network disruption) or to overwrite the startup-config with something else and reload the device. This is a massively disruptive process that can take a large amount of time depending on the device and configuration in play.
In EOS 4.14, Arista added a new option to the
configure command that allows you to replace the running configuration on a live switch. This is a very big deal that doesn’t ...