OLT-1308 Series User’s Guide
97
C
H A P T E R
8
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.
8.1 Introduction to IEEE 802.1Q Tagged VLAN
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.
8.1.1 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 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.
TPID
2 Bytes
User Priority
3 Bits
CFI
1 Bit
VLAN ID
12 bits
Summary of Contents for OLT-1308
Page 2: ......
Page 7: ...Safety Warnings OLT 1308 Series User s Guide 7 ...
Page 8: ...Safety Warnings OLT 1308 Series User s Guide 8 ...
Page 28: ...List of Tables OLT 1308 Series User s Guide 28 ...
Page 30: ...30 ...
Page 34: ...Chapter 1 Introducing the OLT OLT 1308 Series User s Guide 34 ...
Page 38: ...Chapter 2 Hardware Installation and Connection OLT 1308 Series User s Guide 38 ...
Page 44: ...44 ...
Page 58: ...Chapter 5 Initial Setup Example OLT 1308 Series User s Guide 58 ...
Page 72: ...Chapter 6 System Status and Port Statistics OLT 1308 Series User s Guide 72 ...
Page 94: ...Chapter 7 Basic Setting OLT 1308 Series User s Guide 94 ...
Page 96: ...96 ...
Page 106: ...Chapter 8 VLAN OLT 1308 Series User s Guide 106 ...
Page 116: ...Chapter 11 Spanning Tree Protocol OLT 1308 Series User s Guide 116 ...
Page 126: ...Chapter 15 Link Aggregation OLT 1308 Series User s Guide 126 ...
Page 132: ...Chapter 17 Queuing Method OLT 1308 Series User s Guide 132 ...
Page 138: ...Chapter 18 Classifier OLT 1308 Series User s Guide 138 ...
Page 143: ...Chapter 19 Policy OLT 1308 Series User s Guide 143 Figure 53 Policy Example ...
Page 144: ...Chapter 19 Policy OLT 1308 Series User s Guide 144 ...
Page 158: ...158 ...
Page 162: ...Chapter 22 Classification Filter Profile OLT 1308 Series User s Guide 162 ...
Page 172: ...Chapter 23 VLAN Profile OLT 1308 Series User s Guide 172 ...
Page 184: ...Chapter 26 Destination Filter OLT 1308 Series User s Guide 184 ...
Page 188: ...Chapter 27 Port Authentication OLT 1308 Series User s Guide 188 ...
Page 190: ...190 ...
Page 200: ...Chapter 29 Maintenance OLT 1308 Series User s Guide 200 ...
Page 212: ...Chapter 30 Access Control OLT 1308 Series User s Guide 212 ...
Page 218: ...Chapter 32 Syslog OLT 1308 Series User s Guide 218 ...
Page 224: ...Chapter 33 Cluster Management OLT 1308 Series User s Guide 224 ...
Page 228: ...Chapter 34 MAC Table OLT 1308 Series User s Guide 228 ...
Page 232: ...Chapter 36 IGMP Table OLT 1308 Series User s Guide 232 ...
Page 234: ...234 ...
Page 285: ...Chapter 38 Command Examples OLT 1308 Series User s Guide 285 ...
Page 286: ...Chapter 38 Command Examples OLT 1308 Series User s Guide 286 ...
Page 294: ...Chapter 39 Troubleshooting OLT 1308 Series User s Guide 294 ...
Page 296: ...296 ...
Page 302: ...Appendix B Legal Information OLT 1308 Series User s Guide 302 ...