­­­­­­Engineers may run into the following issues when using parser.

• One challenge is the different output formats when command is issued on different devices.
  • The same command is issued on different type of devices, for example, issuing a command [show process cpu] on Cisco IOS Router and Cisco IOS Switch, and the output formats are different. So, if one parser cannot handle all different formats, engineers need to create multiple parsers to deal with this problem.
  • Sometimes even the same command is issued on the same device, the output format may change, for example, issuing a command [show ip route x.x.x.x] on the same device. If the dynamic routing changed, the text format of the command output may change accordingly.
• Another challenge in Intent Template replication is that when engineers need to deal with multiple format output, they must define multiple seed devices to deal with different format with same command. This will increase the definition complexity and performance cost of intent replication.

Multi-format support in parser enables you to handle different output formats with one parser.
 

In the following sections, multi-format support is descripted in the following four aspects.

• Define Multiple Formats for Parser
• Format Qualification
• Impact on Existing Features
• Multi-format Support for NI/NIT