Nortel Contivity 1050, Руководство по настройке

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Chapter 6 Configuring branch office tunnels 127
Nortel VPN Router Configuration — Basic Features
branch offices are configured to use a domain name as a remote endpoint of the
ABOT tunnel. When two initiators at the remote sites need to establish a tunnel, a
DNS query resolves the configured domain name ces.lab.com to the IP address.
DNS returns 1.2.3.4 and 5.6.7.8 for branch one and 5.6.7.8 and 1.2.3.4 for branch
two using Round Robin DNS. The initiator at branch office one uses 1.2.3.4 as a
remote point because it was the first response in the list. The initiator at branch
office two uses 5.6.7.8 as a remote point because it was the first DNS response in
the list.
Figure 24 Load balancing example
Dynamic DNS
Dynamic DNS (DDNS) allows a dynamically addressed host computer to use a
static DNS name. The DNS name system is used both throughout the Internet and
corporations to provide both host to server and host to host communication for
many applications. A DNS name space is typically set up by the system
administrator. Increased use of dynamic IP-based Internet connectivity and the
need to publish well-known host names on the Internet has led to demand for
dynamic DNS capabilities.
The DDNS user is assigned a dynamic IP address, which may change every time
they connect. In general, the address rarely change because in most environments,
users connectivity is outbound so there is no need to advertise a DNS name.
However, users that host a Web server, FTP server, or game servers need to
advertise an address or DNS name to allow their clients to connect to the server.