Chapter 5 Broadband
VMG1312-B10C User’s Guide
62
number of 4,096 VLANs. Note that user priority and VLAN ID are independent of each other. A
frame with VID (VLAN Identifier) of null (0) is called a priority frame, meaning that only the priority
level is significant and the default VID of the ingress port is given as the VID of the frame. Of the
4096 possible VIDs, a VID of 0 is used to identify priority frames and value 4095 (FFF) is reserved,
so the maximum possible VLAN configurations are 4,094.
Multicast
IP packets are transmitted in either one of 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.
Internet Group Multicast Protocol (IGMP) 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.
At start up, the Device queries all directly connected networks to gather group membership. After
that, the Device periodically updates this information.
DNS Server Address Assignment
Use Domain Name System (DNS) to map a domain name to its corresponding IP address and vice
versa, for instance, the IP address of www.zyxel.com is 204.217.0.2. The DNS server is extremely
important because without it, you must know the IP address of a computer before you can access
it.
The Device can get the DNS server addresses in the following ways.
1
The ISP tells you the DNS server addresses, usually in the form of an information sheet, when you
sign up. If your ISP gives you DNS server addresses, manually enter them in the DNS server fields.
2
If your ISP dynamically assigns the DNS server IP addresses (along with the Device’s WAN IP
address), set the DNS server fields to get the DNS server address from the ISP.
IPv6 Addressing
The 128-bit IPv6 address is written as eight 16-bit hexadecimal blocks separated by colons (:). This
is an example IPv6 address
2001:0db8:1a2b:0015:0000:0000:1a2f:0000
.
IPv6 addresses can be abbreviated in two ways:
TPID
2 Bytes
User Priority
3 Bits
CFI
1 Bit
VLAN ID
12 Bits
Summary of Contents for VMG1312-B10C
Page 4: ...Contents Overview VMG1312 B10C User s Guide 4 Diagnostic 265 Troubleshooting 271 ...
Page 14: ...Table of Contents VMG1312 B10C User s Guide 14 ...
Page 15: ...15 PART I User s Guide ...
Page 16: ...16 ...
Page 22: ...Chapter 1 Introducing the Device VMG1312 B10C User s Guide 22 ...
Page 33: ...33 PART II Technical Reference ...
Page 34: ...34 ...
Page 64: ...Chapter 5 Broadband VMG1312 B10C User s Guide 64 ...
Page 100: ...Chapter 6 Wireless VMG1312 B10C User s Guide 100 ...
Page 124: ...Chapter 7 Home Networking VMG1312 B10C User s Guide 124 ...
Page 166: ...Chapter 10 Network Address Translation NAT VMG1312 B10C User s Guide 166 ...
Page 176: ...Chapter 12 Interface Group VMG1312 B10C User s Guide 176 ...
Page 192: ...Chapter 14 Firewall VMG1312 B10C User s Guide 192 ...
Page 198: ...Chapter 16 Parental Control VMG1312 B10C User s Guide 198 ...
Page 208: ...Chapter 18 Certificates VMG1312 B10C User s Guide 208 ...
Page 211: ...Chapter 19 VPN VMG1312 B10C User s Guide 211 Figure 121 IPSec VPN Add ...
Page 224: ...Chapter 20 Log VMG1312 B10C User s Guide 224 ...
Page 234: ...Chapter 24 IGMP Status VMG1312 B10C User s Guide 234 ...
Page 238: ...Chapter 25 xDSL Statistics VMG1312 B10C User s Guide 238 ...
Page 242: ...Chapter 27 User Account VMG1312 B10C User s Guide 242 ...
Page 248: ...Chapter 30 TR 064 VMG1312 B10C User s Guide 248 ...
Page 252: ...Chapter 31 Time Settings VMG1312 B10C User s Guide 252 ...
Page 264: ...Chapter 35 Configuration VMG1312 B10C User s Guide 264 ...
Page 270: ...Chapter 36 Diagnostic VMG1312 B10C User s Guide 270 ...
Page 288: ...Appendix B Legal Information VMG1312 B10C User s Guide 288 ...