ZyXEL 2WG Betriebsanweisung
Chapter 6 LAN Screens
ZyWALL 2WG User’s Guide
148
Multicast
Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 sender - 1
recipient) or Broadcast (1 sender - everybody on the network). Multicast delivers IP packets to
a group of hosts on the network - not everybody and not just 1.
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. The class D IP address is
used to identify host groups and can be in the range 224.0.0.0 to 239.255.255.255. The address
224.0.0.0 is not assigned to any group and is used by IP multicast computers. The address
224.0.0.1 is used for query messages and is assigned to the permanent group of all IP hosts
(including gateways). All hosts must join the 224.0.0.1 group in order to participate in IGMP.
The address 224.0.0.2 is assigned to the multicast routers group.
The ZyWALL supports both IGMP version 1 (IGMP-v1) and IGMP version 2 (IGMP-v2). At
start up, the ZyWALL queries all directly connected networks to gather group membership.
After that, the ZyWALL periodically updates this information. IP multicasting can be enabled/
disabled on the ZyWALL LAN and/or WAN interfaces in the web configurator (LAN; WAN).
Select None to disable IP multicasting on these interfaces.
recipient) or Broadcast (1 sender - everybody on the network). Multicast delivers IP packets to
a group of hosts on the network - not everybody and not just 1.
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. The class D IP address is
used to identify host groups and can be in the range 224.0.0.0 to 239.255.255.255. The address
224.0.0.0 is not assigned to any group and is used by IP multicast computers. The address
224.0.0.1 is used for query messages and is assigned to the permanent group of all IP hosts
(including gateways). All hosts must join the 224.0.0.1 group in order to participate in IGMP.
The address 224.0.0.2 is assigned to the multicast routers group.
The ZyWALL supports both IGMP version 1 (IGMP-v1) and IGMP version 2 (IGMP-v2). At
start up, the ZyWALL queries all directly connected networks to gather group membership.
After that, the ZyWALL periodically updates this information. IP multicasting can be enabled/
disabled on the ZyWALL LAN and/or WAN interfaces in the web configurator (LAN; WAN).
Select None to disable IP multicasting on these interfaces.
WINS
WINS (Windows Internet Naming Service) is a Windows implementation of NetBIOS Name
Server (NBNS) on Windows. It keeps track of NetBIOS computer names. It stores a mapping
table of your network’s computer names and IP addresses. The table is dynamically updated
for IP addresses assigned by DHCP. This helps reduce broadcast traffic since computers can
query the server instead of broadcasting a request for a computer name’s IP address. In this
way WINS is similar to DNS, although WINS does not use a hierarchy (unlike DNS). A
network can have more than one WINS server. Samba can also serve as a WINS server.
Server (NBNS) on Windows. It keeps track of NetBIOS computer names. It stores a mapping
table of your network’s computer names and IP addresses. The table is dynamically updated
for IP addresses assigned by DHCP. This helps reduce broadcast traffic since computers can
query the server instead of broadcasting a request for a computer name’s IP address. In this
way WINS is similar to DNS, although WINS does not use a hierarchy (unlike DNS). A
network can have more than one WINS server. Samba can also serve as a WINS server.
IP Alias
IP alias allows you to partition a physical network into different logical networks over the
same Ethernet interface. The LAN, DMZ or WLAN may all be partitioned in this way.
same Ethernet interface. The LAN, DMZ or WLAN may all be partitioned in this way.
Port Roles
Port Roles allows you to set ports as part of the LAN, DMZ and/or WLAN interface.
6.2 The LAN Screen
Click NETWORK > LAN to open the LAN screen. Use this screen to configure the
ZyWALL’s IP address and other LAN TCP/IP settings as well as the built-in DHCP server
capability that assigns IP addresses and DNS servers to systems that support DHCP client
capability.
ZyWALL’s IP address and other LAN TCP/IP settings as well as the built-in DHCP server
capability that assigns IP addresses and DNS servers to systems that support DHCP client
capability.