ZyXEL Communications MAX-200M1 Series, Руководство пользователя

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ZyXEL MAX-200M1 Series User’s Guide
198 Chapter 20 System
1 The ISP tells you the DNS server addresses, usually in the form of an information sheet,
when you sign up. If your ISP gives you DNS server addresses, enter them in the
DNS
Server fields in the SYSTEM General screen.
2 If the ISP did not give you DNS server information, leave the DNS Server fields in the
SYSTEM General screen set to 0.0.0.0 for the ISP to dynamically assign the DNS server
IP addresses.
20.1.4 Dynamic DNS
Dynamic DNS allows you to update your current dynamic IP address with one or many
dynamic DNS services so that anyone can contact you (in NetMeeting, CU-SeeMe, etc.). You
can also access your FTP server or Web site on your own computer using a domain name (for
instance myhost.dhs.org, where myhost is a name of your choice) that will never change
instead of using an IP address that changes each time you reconnect. Your friends or relatives
will always be able to call you even if they don't know your IP address.
First of all, you need to have registered a dynamic DNS account with www.dyndns.org. This is
for people with a dynamic IP from their ISP or DHCP server that would still like to have a
domain name. The Dynamic DNS service provider will give you a password or key.
Enabling the wildcard feature for your host causes *.yourhost.dyndns.org to be aliased to the
same IP address as yourhost.dyndns.org. This feature is useful if you want to be able to use,
for example, www.yourhost.dyndns.org and still reach your hostname.
Note: If you have a private WAN IP address, then you cannot use Dynamic DNS.
20.1.5 Pre-defined NTP Time Servers List
The ZyXEL Device uses the following pre-defined list of NTP time servers if you do not
specify a time server or it cannot synchronize with the time server you specified.
Note: The ZyXEL Device can use this pre-defined list of time servers regardless of
the Time Protocol you select.
When the ZyXEL Device uses the pre-defined list of NTP time servers, it randomly selects
one server and tries to synchronize with it. If the synchronization fails, then the ZyXEL
Device goes through the rest of the list in order from the first one tried until either it is
successful or all the pre-defined NTP time servers have been tried.
Table 82 Pre-defined NTP Time Servers
ntp1.cs.wisc.edu
ntp1.gbg.netnod.se
ntp2.cs.wisc.edu
tock.usno.navy.mil
ntp3.cs.wisc.edu
ntp.cs.strath.ac.uk