ZyXEL Communications ZyAir G-2000 PlusV2 User Manual page 77

Table 19 LAN IP
LABEL
First DNS Server
Second DNS Server
Third DNS Server
LAN TCP/IP
IP Address
IP Subnet Mask
RIP Direction
RIP Version
Multicast
Windows Networking (NetBIOS over TCP/IP): NetBIOS (Network Basic Input/Output System) are TCP
or UDP broadcast packets that enable a computer to connect to and communicate with a LAN. For
some dial-up services such as PPPoE or PPTP, NetBIOS packets cause unwanted calls. However it
may sometimes be necessary to allow NetBIOS packets to pass through to the WAN in order to find a
computer on the WAN.
Chapter 5 LAN Screens
DESCRIPTION
Select From ISP if your ISP dynamically assigns DNS server information (and
the ZyXEL device's WAN IP address). The field to the right displays the (read-
only) DNS server IP address that the ISP assigns.
Select User-Defined if you have the IP address of a DNS server. Enter the DNS
server's IP address in the field to the right. If you chose User-Defined, but leave
the IP address set to 0.0.0.0, User-Defined changes to None after you click
Apply. If you set a second choice to User-Defined, and enter the same IP
address, the second User-Defined changes to None after you click Apply.
Select DNS Relay to have the ZyXEL device act as a DNS proxy. The ZyXEL
device's LAN IP address displays in the field to the right (read-only). The ZyXEL
device tells the DHCP clients on the LAN that the ZyXEL device itself is the DNS
server. When a computer on the LAN sends a DNS query to the ZyXEL device,
the ZyXEL device forwards the query to the ZyXEL device's system DNS server
(configured in the SYSTEM General screen) and relays the response back to the
computer. You can only select DNS Relay for one of the three servers; if you
select DNS Relay for a second or third DNS server, that choice changes to None
after you click Apply.
Select None if you do not want to configure DNS servers. If you do not configure
a DNS server, you must know the IP address of a computer in order to access it.
Type the IP address of your ZyXEL device in dotted decimal notation 192.168.1.1
(factory default).
The subnet mask specifies the network number portion of an IP address. Your
ZyXEL device will automatically calculate the subnet mask based on the IP
address that you assign. Unless you are implementing subnetting, use the subnet
mask computed by the ZyXEL device 255.255.255.0.
RIP (Routing Information Protocol, RFC1058 and RFC 1389) allows a router to
exchange routing information with other routers. The RIP Direction field controls
the sending and receiving of RIP packets. Select the RIP direction from Both/In
Only/Out Only/None. When set to Both or Out Only, the ZyXEL device will
broadcast its routing table periodically. When set to Both or In Only, it will
incorporate the RIP information that it receives; when set to None, it will not send
any RIP packets and will ignore any RIP packets received. Both is the default.
The RIP Version field controls the format and the broadcasting method of the
RIP packets that the ZyXEL device sends (it recognizes both formats when
receiving). RIP-1 is universally supported but RIP-2 carries more information.
RIP-1 is probably adequate for most networks, unless you have an unusual
network topology. Both RIP-2B and RIP-2M sends the routing data in RIP-2
format; the difference being that RIP-2B uses subnet broadcasting while RIP-2M
uses multicasting. Multicasting can reduce the load on non-router machines since
they generally do not listen to the RIP multicast address and so will not receive
the RIP packets. However, if one router uses multicasting, then all routers on
your network must use multicasting, also. By default, RIP direction is set to Both
and the Version set to RIP-1.
Select IGMP V-1 or IGMP V-2 or None. IGMP (Internet Group Multicast Protocol)
is a network-layer protocol used to establish membership in a Multicast group - it
is not used to carry user data. IGMP version 2 (RFC 2236) is an improvement
over version 1 (RFC 1112) but IGMP version 1 is still in wide use. If you would
like to read more detailed information about interoperability between IGMP
version 2 and version 1, please see sections 4 and 5 of RFC 2236.
ZyXEL G-2000 Plus v2 User's Guide
77