MES-3528 User’s Guide
91
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 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.
9.1.1 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
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Страница 8: ...Safety Warnings MES 3528 User s Guide 8 ...
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Страница 32: ...Chapter 2 Hardware Installation and Connection MES 3528 User s Guide 32 ...
Страница 42: ...Chapter 3 Hardware Overview MES 3528 User s Guide 42 ...
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Страница 60: ...Chapter 5 Initial Setup Example MES 3528 User s Guide 60 ...
Страница 76: ...Chapter 7 System Status and Port Statistics MES 3528 User s Guide 76 ...
Страница 88: ...Chapter 8 Basic Setting MES 3528 User s Guide 88 ...
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Страница 109: ...Chapter 9 VLAN MES 3528 User s Guide 109 Figure 57 Port Based VLAN Setup Port Isolation ...
Страница 114: ...Chapter 10 Static MAC Forward Setup MES 3528 User s Guide 114 ...
Страница 146: ...Chapter 14 Bandwidth Control MES 3528 User s Guide 146 ...
Страница 160: ...Chapter 17 Link Aggregation MES 3528 User s Guide 160 ...
Страница 168: ...Chapter 19 Port Security MES 3528 User s Guide 168 ...
Страница 180: ...Chapter 21 Policy Rule MES 3528 User s Guide 180 ...
Страница 192: ...Chapter 23 VLAN Stacking MES 3528 User s Guide 192 ...
Страница 231: ...Chapter 26 IP Source Guard MES 3528 User s Guide 231 Figure 120 DHCP Snooping ...
Страница 248: ...Chapter 26 IP Source Guard MES 3528 User s Guide 248 ...
Страница 257: ...257 PART IV IP Application Static Route 259 Differentiated Services 263 DHCP 267 ...
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Страница 262: ...Chapter 29 Static Route MES 3528 User s Guide 262 ...
Страница 274: ...Chapter 31 DHCP MES 3528 User s Guide 274 ...
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Страница 284: ...Chapter 32 Maintenance MES 3528 User s Guide 284 ...
Страница 306: ...Chapter 33 Access Control MES 3528 User s Guide 306 ...
Страница 312: ...Chapter 35 Syslog MES 3528 User s Guide 312 ...
Страница 320: ...Chapter 36 Cluster Management MES 3528 User s Guide 320 ...
Страница 324: ...Chapter 37 MAC Table MES 3528 User s Guide 324 ...
Страница 329: ...329 PART VI Troubleshooting Product Specifications Troubleshooting 331 Product Specifications 335 ...
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Страница 342: ...Chapter 41 Product Specifications MES 3528 User s Guide 342 ...
Страница 343: ...343 PART VII Appendices and Index Changing a Fuse 345 Common Services 347 Legal Information 351 Index 355 ...
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Страница 346: ...Appendix A Changing a Fuse MES 3528 User s Guide 346 ...
Страница 354: ...Appendix C Legal Information MES 3528 User s Guide 354 ...
Страница 364: ...Index MES 3528 User s Guide 364 ...