Originally posted by The Prohacker
Thats if you are on a small network.. Larger networks will have multiple boarder and core routers.. Also VLANs can limit you on what kind of IPs you can bind...
That is true under certain circumstances, but....
Your ISP should be able to route additional netblocks to the gateway IP of your existing netblock and associated VLAN.
The netblocks they route should not be associated with other VLANS already configured on the switch.
Let's say they assigned you a /27 (184.108.40.206/27)
And this is bound to a VLAN interface you use. It's gateway/router IP is 220.127.116.11
The ISP should be able to do this:
ip route 18.104.22.168 255.255.255.224 22.214.171.124
Doing this will send an additional /27 from a different network over your existing 126.96.36.199/27 down to your switch or server.
Then all you need to do is configure machines connected to your small switch, hub or whatever to IP's on the 188.8.131.52/27 network and tell them to use 184.108.40.206 as the gateway to get out.
I don't know wht your ISP can't do this. It is totally normal.... unless *ALL* of their IP space is already assigned to different VLAN interfaces on their switch. In which case they would not have free netblocks available for this type of routing.
Yes, I am a network engineer.