Chapter 9 VLAN
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dynamically through GVRP. The VLAN ID associates a frame with a specific VLAN
and provides the information that switches need to process the frame across the
network. A tagged frame is four bytes longer than an untagged frame and
contains two bytes of TPID (Tag Protocol Identifier, residing within the type/length
field of the Ethernet frame) and two bytes of TCI (Tag Control Information, starts
after the source address field of the Ethernet frame).
The CFI (Canonical Format Indicator) is a single-bit flag, always set to zero for
Ethernet switches. If a frame received at an Ethernet port has a CFI set to 1, then
that frame should not be forwarded as it is to an untagged port. The remaining
twelve bits define the VLAN ID, giving a possible maximum 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.
9.3.2 Forwarding Tagged and Untagged Frames
Each port on the Switch is capable of passing tagged or untagged frames. To
forward a frame from an 802.1Q VLAN-aware switch to an 802.1Q VLAN-unaware
switch, the Switch first decides where to forward the frame and then strips off the
VLAN tag. To forward a frame from an 802.1Q VLAN-unaware switch to an 802.1Q
VLAN-aware switch, the Switch first decides where to forward the frame, and then
inserts a VLAN tag reflecting the ingress port's default VID. The default PVID is
VLAN 1 for all ports, but this can be changed.
A broadcast frame (or a multicast frame for a multicast group that is known by the
system) is duplicated only on ports that are members of the VID (except the
ingress port itself), thus confining the broadcast to a specific domain.
9.3.3 Automatic VLAN Registration
GARP and GVRP are the protocols used to automatically register VLAN
membership across switches.
9.3.4 GARP
GARP (Generic Attribute Registration Protocol) allows network switches to register
and de-register attribute values with other GARP participants within a bridged
TPID
2 Bytes
User Priority
3 Bits
CFI
1 Bit
VLAN ID
12 bits
Summary of Contents for GS2200-24 Series
Page 2: ......
Page 8: ...Safety Warnings GS2200 24 User s Guide 8 ...
Page 22: ...Table of Contents GS2200 24 User s Guide 22 ...
Page 24: ...24 ...
Page 30: ...Chapter 1 Getting to Know Your Switch GS2200 24 User s Guide 30 ...
Page 34: ...Chapter 2 Hardware Installation and Connection GS2200 24 User s Guide 34 ...
Page 42: ...42 ...
Page 70: ...Chapter 7 System Status and Port Statistics GS2200 24 User s Guide 70 ...
Page 84: ...Chapter 8 Basic Setting GS2200 24 User s Guide 84 ...
Page 86: ...86 ...
Page 104: ...Chapter 9 VLAN GS2200 24 User s Guide 104 Figure 51 Port Based VLAN Setup Port Isolation ...
Page 110: ...Chapter 10 Static MAC Forward Setup GS2200 24 User s Guide 110 ...
Page 138: ...Chapter 13 Spanning Tree Protocol GS2200 24 User s Guide 138 ...
Page 142: ...Chapter 14 Bandwidth Control GS2200 24 User s Guide 142 ...
Page 146: ...Chapter 15 Broadcast Storm Control GS2200 24 User s Guide 146 ...
Page 150: ...Chapter 16 Mirroring GS2200 24 User s Guide 150 ...
Page 160: ...Chapter 17 Link Aggregation GS2200 24 User s Guide 160 ...
Page 168: ...Chapter 19 Port Security GS2200 24 User s Guide 168 ...
Page 180: ...Chapter 21 Policy Rule GS2200 24 User s Guide 180 ...
Page 192: ...Chapter 23 VLAN Stacking GS2200 24 User s Guide 192 ...
Page 214: ...Chapter 25 AAA GS2200 24 User s Guide 214 ...
Page 240: ...Chapter 26 IP Source Guard GS2200 24 User s Guide 240 ...
Page 250: ...Chapter 28 Layer 2 Protocol Tunneling GS2200 24 User s Guide 250 ...
Page 251: ...251 PART IV IP Application Static Route 253 Differentiated Services 257 DHCP 261 ...
Page 252: ...252 ...
Page 256: ...Chapter 29 Static Route GS2200 24 User s Guide 256 ...
Page 270: ...270 ...
Page 300: ...Chapter 33 Access Control GS2200 24 User s Guide 300 ...
Page 306: ...Chapter 35 Syslog GS2200 24 User s Guide 306 ...
Page 314: ...Chapter 36 Cluster Management GS2200 24 User s Guide 314 ...
Page 318: ...Chapter 37 MAC Table GS2200 24 User s Guide 318 ...
Page 324: ...324 ...
Page 336: ...Chapter 41 Product Specifications GS2200 24 User s Guide 336 ...
Page 338: ...338 ...
Page 340: ...Appendix A Changing a Fuse GS2200 24 User s Guide 340 ...
Page 348: ...Appendix C Legal Information GS2200 24 User s Guide 348 ...
Page 358: ...Index GS2200 24 User s Guide 358 ...