Bug#867625: isc-dhcp: dhclient-script doesn't use configured metric for rfc3442 classless routes, launchpad bug #1664352

[M. Buecher]

Recently I just had the same issue and came to the same solution, 
although with a little bit more sanitized usage of variables.

I created a bugfix branch, but I am not able to create a merge request 
for the original repository of the dhcp team:
https://salsa.debian.org/maddes_b/isc-dhcp/-/commit/24b230483b27c4387a805893234decf10684d2f6
https://salsa.debian.org/dhcp-team/isc-dhcp
Please consider fixing also in the current Debian release.

Kind regards
Maddes