XGS4700-48F User’s Guide
119
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
Содержание XGS4700 Series
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Страница 8: ...Safety Warnings XGS4700 48F User s Guide 8...
Страница 24: ...Table of Contents XGS4700 48F User s Guide 24...
Страница 25: ...25 PART I User s Guide...
Страница 26: ...26...
Страница 32: ...Chapter 1 Getting to Know Your Switch XGS4700 48F User s Guide 32...
Страница 54: ...Chapter 3 Hardware Overview XGS4700 48F User s Guide 54...
Страница 97: ...97 PART II Technical Reference...
Страница 98: ...98...
Страница 104: ...Chapter 7 System Status and Port Statistics XGS4700 48F User s Guide 104...
Страница 118: ...Chapter 8 Basic Setting XGS4700 48F User s Guide 118...
Страница 138: ...Chapter 9 VLAN XGS4700 48F User s Guide 138...
Страница 142: ...Chapter 10 Static MAC Forward Setup XGS4700 48F User s Guide 142...
Страница 174: ...Chapter 14 Bandwidth Control XGS4700 48F User s Guide 174...
Страница 188: ...Chapter 17 Link Aggregation XGS4700 48F User s Guide 188...
Страница 198: ...Chapter 18 Port Authentication XGS4700 48F User s Guide 198...
Страница 216: ...Chapter 21 Policy Rule XGS4700 48F User s Guide 216...
Страница 260: ...Chapter 25 AAA XGS4700 48F User s Guide 260...
Страница 284: ...Chapter 26 IP Source Guard XGS4700 48F User s Guide 284...
Страница 316: ...Chapter 32 Error Disable XGS4700 48F User s Guide 316...
Страница 320: ...Chapter 33 Static Route XGS4700 48F User s Guide 320...
Страница 328: ...Chapter 35 RIP XGS4700 48F User s Guide 328...
Страница 384: ...Chapter 42 ARP Learning XGS4700 48F User s Guide 384...
Страница 420: ...Chapter 45 Access Control XGS4700 48F User s Guide 420...
Страница 426: ...Chapter 47 Syslog XGS4700 48F User s Guide 426...
Страница 434: ...Chapter 48 Cluster Management XGS4700 48F User s Guide 434...
Страница 438: ...Chapter 49 MAC Table XGS4700 48F User s Guide 438...
Страница 442: ...Chapter 50 IP Table XGS4700 48F User s Guide 442...
Страница 446: ...Chapter 52 Routing Table XGS4700 48F User s Guide 446...
Страница 454: ...Chapter 54 Troubleshooting XGS4700 48F User s Guide 454...
Страница 464: ...Chapter 55 Product Specifications XGS4700 48F User s Guide 464...
Страница 473: ...Appendix B Legal Information XGS4700 48F User s Guide 473...
Страница 474: ...Appendix B Legal Information XGS4700 48F User s Guide 474...