LinuxQuestions.org - Stuck! How do I route a 20 x /24 subnets in Ubuntu 14?

Trying to bind 20 x /24 subnets in Ubuntu 14 Server (for proxy/VPN) but I'm stuck here. These are diversified /24 subnets.

I tried the below method via script called addips.sh

Code:

for i in $(seq 3 254); do echo "auto em1:$i

iface em1:$i inet static

address xxx.xxx.16.$i                                                                              

netmask 255.255.255.0                                                                      

" >> virthosts; done

But, I noticed that this happened now:

Each /24 subnet it outputted started off at #1 again instead of 255, 256, 257, etc all the way through consecutively for all 20 x /24 subnets

Code:

auto em1:1

auto em1:254



Then again...



auto em1:1

...

How can I properly change this so it does reset at #1? em1 is the NIC Ethernet port (primary) and only port used too.

I also want to make sure these are permanent, they stick after a server reboot.