assign network or broadcast address as regular ip add

Hi,
i got from my isp (eurpean adsl provider) ip range of 4 fixed addresses with /30 mask, of which are normally 2 usable - 1 statically assigned to public iface of linux server/router, 1 for "lan" interface of dsl router attached to public side of server. But I need to connect just one more device in this small public subnet, so is it possible to use network or broadcast addres of this range as regular ip address ? If yes, how to make it work ? I need only standard routing, no broadcasts on this small network. Which net/broadcast address would be easier to configure (to which device) ? I wouldn't pay for 8ip range if it'd be possible to do it with easy trick. Thanks,
Ivan

Unless you need this additional device to be a public server. You could use NAT to have any number of private IPs you want, additional devices would connect to internet and browse normally. Check your router manuals and see if it supports NAT or not.

But I need to connect just one more device in this small public subnet, so is it possible to use network or broadcast addres of this range as regular ip address ?

No.

I wouldn't pay for 8ip range if it'd be possible to do it with easy trick. Thanks,
Ivan

If you don't want to pay for a /29, you could see if they could give you a second /30, for free or at least cheaper than a /29.

Thanks, pretty straightfoward answer
But I'll try once more - could it be possible this way ?
e.g. - i buy from provider ip address 82.107.100.100/30 - it means all this address space will be routed to my dsl modem. So normally usable would be address .101/30 (for DSL modem) and .102/30 (for server).
But when I assign .102/29 to server, .101/29 to modem and .100/29 to occasionaly used management nic, and to all three devices same network address .96 and broadcast .103, could it work ?
Ivan

It will not work because your providers router will not be configured to route the larger subnet of .96/29 traffic back to you.