<br /><br />When you get a "back address" - do you mean a "class c" or private/internal IP address? <br /><br />192.168.xxx.xxx or 10.xxx.xxx.xxx are class c IP addresses.<br /><br />In this scenario, they are probably using NAT, or Network Address Translation where you hit an external, public IP address and their firewall passes your traffic through to their internal network but probably, for security, only allows you access to certain ports.<br /><br />If it shows their internal IP address, it's not a very secure network. Pardon the impertinence but why do you use the handle tomatolord? If I asked the question before, and you have answered it, please tell me again. I thank you.
Incorrect on both counts. By definition a Class C address uses the last 8 bits for the host field and where the first 3 bits of the 24-bit binary network field are set to '110'.<br /><br />192.168.xxx.xxx is not a class C address because you're reserving the last 16 bits to define the host field, even though this netblock falls within the range of addresses reserved for Class C networks. <br /><br />10.xxx.xxx.xxx is not a class C address because you're reserving the last 24 bits to define the host field, and this netblock falls within the range of addresses reserved for Class A networks (first bit of the network field is set to '0'). <br /><br />Both of the netblocks you reference are part of IANA's private address space allocation, namely 10.x.x.x, 172.16.x.x-172.31.x.x, and 192.168.0.x-192.168.255.x (a.k.a. RFC-1918 address space)<br /><br />of course with the advent of CIDR (classless inter-domain routing) you can carve up these netblocks as you choose within your own internal network to meet your own needs
