User's Manual

Chapter 52 System
ISG50 User’s Guide
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The following table describes the labels in this screen.
Table 269 Configuration > System > DNS
LABEL DESCRIPTION
Address/PTR
Record
This record specifies the mapping of a Fully-Qualified Domain Name (FQDN) to
an IP address. An FQDN consists of a host and domain name. For example,
www.zyxel.com.tw is a fully qualified domain name, where “www” is the host,
“zyxel” is the third-level domain, “com” is the second-level domain, and “tw” is
the top level domain.
Add Click this to create a new entry.
Edit Double-click an entry or select it and click Edit to be able to modify the entry’s
settings.
Remove To remove an entry, select it and click Remove. The ISG50 confirms you want
to remove it before doing so. Note that subsequent entries move up by one
when you take this action.
# This is the index number of the address/PTR record.
FQDN This is a host’s fully qualified domain name.
IP Address This is the IP address of a host.
Domain Zone
Forwarder
This specifies a DNS server’s IP address. The ISG50 can query the DNS server to
resolve domain zones for features like VPN, DDNS and the time server.
When the ISG50 needs to resolve a domain zone, it checks it against the domain
zone forwarder entries in the order that they appear in this list.
Add Click this to create a new entry. Select an entry and click Add to create a new
entry after the selected entry.
Edit Double-click an entry or select it and click Edit to be able to modify the entry’s
settings.
Remove To remove an entry, select it and click Remove. The ISG50 confirms you want
to remove it before doing so. Note that subsequent entries move up by one
when you take this action.
Move To change an entry’s position in the numbered list, select the method and click
Move to display a field to type a number for where you want to put it and press
[ENTER] to move the rule to the number that you typed.
# This is the index number of the domain zone forwarder record. The ordering of
your rules is important as rules are applied in sequence.
A hyphen (-) displays for the default domain zone forwarder record. The default
record is not configurable. The ISG50 uses this default record if the domain zone
that needs to be resolved does not match any of the other domain zone
forwarder records.
Domain Zone A domain zone is a fully qualified domain name without the host. For example,
zyxel.com.tw is the domain zone for the www.zyxel.com.tw fully qualified
domain name.
A “*” means all domain zones.
Type This displays whether the DNS server IP address is assigned by the ISP
dynamically through a specified interface or configured manually (User-
Defined).
DNS Server This is the IP address of a DNS server. This field displays N/A if you have the
ISG50 get a DNS server IP address from the ISP dynamically but the specified
interface is not active.
Query Via This is the interface through which the ISG50 sends DNS queries to the entry’s
DNS server. If the ISG50 connects through a VPN tunnel, tunnel displays.
MX Record (for My
FQDN)
A MX (Mail eXchange) record identifies a mail server that handles the mail for a
particular domain.