Debian jessie, network not starting after installation?

Question

Debian

In the organization we are making the transition from window sills to open source, we use debian netinstall as a distribution kit.
I noticed that since recently, after installing debian from the off repository on the machine, after installation there is no defaul route, only those routes that the router gives (mikrotik ccr1036-12g-4s) are available. To eliminate it, you have to write the command to add a default route to the initialization script, but this is not a panacea if there is such a crutch on 860 computers, suddenly the machine will move to another subnet or we will change the route address itself.
UP log dubug dhcp https://docs.google.com/document/d/1l8bgUjVcOxfMk
...

Answer 1

replace
/etc/dhcp/dhclient-enter-hooks.d/debug
/etc/dhcp/dhclient-exit-hooks.d/debug
line RUN="no" with RUN="yes"
turn off raise network
watch /tmp/ dhclient-script.debug