As was stated by another responder, the subnet mask only affects how hosts on that network treat the IP's within the same network.
The routing infrastructure doesn't really care that the hosts can't use the network or broadcast address, unless it has an interface inside that network.
It's common in our colo environments to have a /29 frontside block, which allows for 4 hosts and 2 virtual interfaces (HSRP), with /27 blocks routed to the virtual interface on the customer firewalls. Since the customer is running NAT, the /27 is translated. This allows all 32 IP addresses in that /27 to be translated to internal hosts behind the firewalls.
You could do the same thing with your AMPR allocation. Since the tunnel IP is your public IP address, you can simply translate the entire /29 (8 IP's) to internal private hosts and use all 8. If you choose to have a separate network segment with it's own interface, you'd only have 5 hosts, 1 gateway, and the 2 addresses used by subnetting.
--Will
On 8/24/16 5:59 AM, R P wrote:
One of our gateway got 8 IP ADDRESSES 44.138.0.8/39 Can the first address 44.238.0.8 be used ? or it reserved for networking only ? and i have to choose ip address only in the range of the 9-14 ? if the answer is that it can not be used how the main router at UCSD treat for ping attempts coming for 44.138.0.8 ? does it pass it ? or ignore it ? all is assured that the IP is defined at the AMPR DNS...