ZyXEL Communications Parental Control Gateway HS100/HS100W - Manual (Page 79)

HomeSafe User’s Guide
5-2 LAN Screens
packets. When set to Both or Out Only, the HomeSafe 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.
RIP Version controls the format and the broadcasting method of the RIP packets that the
HomeSafe 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 send 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 RIP Version to RIP-1.
5.3.4 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 HomeSafe supports both IGMP version 1 (IGMP-v1) and IGMP version 2 (IGMP-v2). At
start up, the HomeSafe queries all directly connected networks to gather group membership. After
that, the HomeSafe periodically updates this information. IP multicasting can be enabled/disabled
on the HomeSafe LAN and/or WAN interfaces in the web configurator (LAN; WAN). Select
None to disable IP multicasting on these interfaces.
5.4 Any IP
Traditionally, you must set the IP addresses and the subnet masks of a computer and the
HomeSafe to be in the same subnet to allow the computer to access the Internet (through the
HomeSafe). In cases where your computer is required to use a static IP address in another
network, you may need to manually configure the network settings of the computer every time
you want to access the Internet via the HomeSafe.
With the Any IP feature and NAT enabled, the HomeSafe allows a computer to access the
Internet without changing the network settings (such as IP address and subnet mask) of the
computer, when the IP addresses of the computer and the HomeSafe are not in the same subnet.
Whether a computer is set to use a dynamic or static (fixed) IP address, you can simply connect
the computer to the HomeSafe and access the Internet.
The following figure depicts a scenario where a computer is set to use a static private IP address
in the corporate environment. In a residential house where a HomeSafe is installed, you can still