ZyXEL g-2000 plusv2 Guía Del Usuario

ZyXEL G-2000 Plus v2 User’s Guide

Chapter 5 LAN Screens

77

First DNS Server
Second DNS Server
Third DNS Server 

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.

LAN TCP/IP

IP Address

Type the IP address of your ZyXEL device in dotted decimal notation 192.168.1.1 

(factory default).

IP Subnet Mask

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 Direction

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.

RIP Version

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.

Multicast

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.

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.

Table 19   LAN IP