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XGS-4526/4528F/4728F User’s Guide
117
C
H A P T E R
9
VLAN
The type of screen you see here depends on the VLAN Type you selected in the
Switch Setup screen. This chapter shows you how to configure 802.1Q tagged
and port-based VLANs.
9.1 Introduction to IEEE 802.1Q Tagged VLANs
A tagged VLAN uses an explicit tag (VLAN ID) in the MAC header to identify the
VLAN membership of a frame across bridges - they are not confined to the switch
on which they were created. The VLANs can be created statically by hand or
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 for the TPID (Tag Protocol Identifier, residing within the type/
length field of the Ethernet frame) and two bytes for the TCI (Tag Control
Information, starting 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 the value 4095 (FFF) is reserved, so the maximum possible
number of VLAN configurations is 4,094.
9.1.1 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
TPID
2 Bytes
User Priority
3 Bits
CFI
1 Bit
VLAN ID
12 bits
Summary of Contents for XGS-4528F
Page 2: ......
Page 8: ...Safety Warnings XGS 4526 4528F 4728F User s Guide 8...
Page 24: ...Table of Contents XGS 4526 4528F 4728F User s Guide 24...
Page 25: ...25 PART I User s Guide...
Page 26: ...26...
Page 32: ...Chapter 1 Getting to Know Your Switch XGS 4526 4528F 4728F User s Guide 32...
Page 36: ...Chapter 2 Hardware Installation and Connection XGS 4526 4528F 4728F User s Guide 36...
Page 93: ...93 PART II Technical Reference...
Page 94: ...94...
Page 100: ...Chapter 7 System Status and Port Statistics XGS 4526 4528F 4728F User s Guide 100...
Page 116: ...Chapter 8 Basic Setting XGS 4526 4528F 4728F User s Guide 116...
Page 136: ...Chapter 9 VLAN XGS 4526 4528F 4728F User s Guide 136...
Page 140: ...Chapter 10 Static MAC Forward Setup XGS 4526 4528F 4728F User s Guide 140...
Page 172: ...Chapter 14 Bandwidth Control XGS 4526 4528F 4728F User s Guide 172...
Page 186: ...Chapter 17 Link Aggregation XGS 4526 4528F 4728F User s Guide 186...
Page 196: ...Chapter 18 Port Authentication XGS 4526 4528F 4728F User s Guide 196...
Page 214: ...Chapter 21 Policy Rule XGS 4526 4528F 4728F User s Guide 214...
Page 258: ...Chapter 25 AAA XGS 4526 4528F 4728F User s Guide 258...
Page 282: ...Chapter 26 IP Source Guard XGS 4526 4528F 4728F User s Guide 282...
Page 314: ...Chapter 32 Error Disable XGS 4526 4528F 4728F User s Guide 314...
Page 318: ...Chapter 33 Private VLAN XGS 4526 4528F 4728F User s Guide 318...
Page 322: ...Chapter 34 Static Route XGS 4526 4528F 4728F User s Guide 322...
Page 330: ...Chapter 36 RIP XGS 4526 4528F 4728F User s Guide 330...
Page 386: ...Chapter 43 ARP Learning XGS 4526 4528F 4728F User s Guide 386...
Page 396: ...Chapter 45 Maintenance XGS 4526 4528F 4728F User s Guide 396...
Page 442: ...Chapter 49 Cluster Management XGS 4526 4528F 4728F User s Guide 442...
Page 446: ...Chapter 50 MAC Table XGS 4526 4528F 4728F User s Guide 446...
Page 450: ...Chapter 51 IP Table XGS 4526 4528F 4728F User s Guide 450...
Page 454: ...Chapter 53 Routing Table XGS 4526 4528F 4728F User s Guide 454...
Page 462: ...Chapter 55 Troubleshooting XGS 4526 4528F 4728F User s Guide 462...
Page 472: ...Chapter 56 Product Specifications XGS 4526 4528F 4728F User s Guide 472...
Page 480: ...Appendix B Legal Information XGS 4526 4528F 4728F User s Guide 480...