Route-Map - Managing sequence numbers
You can add, delete, or reorder sequence numbers in a Cisco IOS Route-map without impacting the current state of the network. Cisco IOS assigns sequence numbers in increments of 10 by default, allowing you to insert new statements between existing ones without redoing the entire configuration.
- Adding a Sequence: Specify a new number with the
route-mapcommand. For example, if you have sequences 10 and 20, you can add sequence 15 with the commandroute-map MAP_NAME permit 15. - Deleting a Sequence: Use the
noform of theroute-mapcommand, likeno route-map MAP_NAME permit 10. - Reordering Sequences: Remove and re-add the sequences in the desired order. This can be disruptive, so prepare the commands beforehand and apply them quickly to minimize impact.
Changes to route-maps take effect immediately, so it is advisable to make these changes during a maintenance window. For production networks, changes should be thoroughly tested in a lab environment before implementation to catch possible mistakes and minimize network impact.
Links:
https://forum.networklessons.com/t/how-to-filter-prefixes-with-distribute-list/943/27?u=lagapidis
https://networklessons.com/cisco/ccnp-route/introduction-to-route-maps