When Should I modify the MAC address for WAN/global port settings?
Some ISPs identify their clients by accessing the MAC address and the host names. Therefore, this information is required for identification purposes. The MAC address required for WAN/global port settings is the adapter address for the IP Sharing you are now configuring. Generally, it should be the one you already registered in your ISP, and thus, there should be no need to modify it. However, there is an exception when the IP sharing device you are now using is not the one with the MAC address that you registered in your ISP. If this is the case, it then becomes necessary to modify the MAC address.
What is DMZ?
DMZ is an abbreviation for “demilitarized zone”. A DMZ is a sort of middle region between an external network, such as the Internet, and a company's Intranet or internal network. It is a subnet that contains a firewall and proxy server, which exist either in separate servers or in a single server. The firewall connects to an external firewall on the Internet side, which may be at the ISP's location and is often called a "boundary router." The double firewall architecture adds an extra measure of security for the Intranet.
What is Dynamic DNS (DDNS)?
Through the Dynamic DNS service, an IP Registry provides a public central database where information such as email addresses, hostnames, IPs etc. can be stored and retrieved. If your DNS server uses an IP associated with dynamic IP, DDNS will resolve this issue. The Dynamic DNS service acts much the same way as
Why "Dynamic DNS?"
With Dynamic DNS support, you can alias a dynamic IP address to a static hostname, allowing the host to be more easily accessible from various locations