advantage of a route map that leads to no where?

[baselzind]

i used to have a route map on all my interface vlans that leads internet traffic to a proxy. Afterward the proxy was disabled and the route map ACL was modified to deny the vlans subnet from going to the proxy ip and go normally to the firewall and allow everything else to the old unused proxy ip. My question is there any use to keep the old configuration? like to lead any other non-vlan ip that is coming to the vlan interface on the core switch to a dead end?

[M02@rt37 · Accepted solution]

Hello @baselzind 

While it might act as a form of "blackhole" for traffic that matches certain criteria, it introduces unnecessary complexity and could potentially cause confusion in the future (?)

If not necessary now, I prefer clean that configuration, and if I need blackholing I will do that with proper prefix-list or route-map with specific description/remark.

[paul driver]

Hello
For you site router - which usually has a default route towards the wan  you could use a null route as well so the rtr will not forward traffic back towards the isp for any non active vlan within you lan subnet ip range
Example -

site lan subnet ip range - 192.168.0.0/20
ip route 0.0.0.0 0.0.0.0 x/x 10.1.1.1. name default -route-towards-wan
Ip route 192.168.0.0 255.255.240.0 null0

[baselzind]

please can you explain further ? what does the 10.1.1.1 supposed to represent and what does the second route function?