D-Link DES-3226L User Manual - Page 85

Port VLAN ID, Unfortunately

Get D-Link DES-3226L - Switch PDF manuals and user guides
UPC - 790069262722
View all D-Link DES-3226L manuals
Add to My Manuals
Save this manual to your list of manuals

Page 85 highlights

DES-3226L Layer 2 Fast Ethernet Switch User's Guide Figure 6-12. IEEE 802.1Q Tag The EtherType and VLAN ID are inserted after the MAC source address, but before the original EtherType/Length or Logical Link Control. Because the packet is now a bit longer than it was originally, the Cyclic Redundancy Check (CRC) must be recalculated. Figure 6-13. Adding an IEEE 802.1Q Tag Port VLAN ID Packets that are tagged (are carrying the 802.1Q VID information) can be transmitted from one 802.1Q compliant network device to another with the VLAN information intact. This allows 802.1Q VLANs to span network devices (and indeed, the entire network, if all network devices are 802.1Q compliant). Unfortunately, not all network devices are 802.1Q compliant. These devices are referred to as tag-unaware. 802.1Q devices are referred to as tag-aware. Prior to the adoption of 802.1Q VLANs, port-based and MAC-based VLANs were in common use. These VLANs relied upon a Port VLAN ID (PVID) to forward packets. A 73

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
DES-3226L Layer 2
Fast Ethernet Switch User’s Guide
Figure 6-12.
IEEE 802.1Q Tag
The EtherType and VLAN ID are inserted after the MAC source address, but before the
original EtherType/Length or Logical Link Control. Because the packet is now a bit longer
than it was originally, the Cyclic Redundancy Check (CRC) must be recalculated.
Figure 6-13.
Adding an IEEE 802.1Q Tag
Port VLAN ID
Packets that are tagged (are carrying the 802.1Q VID information) can be transmitted from
one 802.1Q compliant network device to another with the VLAN information intact. This
allows 802.1Q VLANs to span network devices (and indeed, the entire network, if all network
devices are 802.1Q compliant).
Unfortunately, not all network devices are 802.1Q compliant. These devices are referred to as
tag-unaware.
802.1Q devices are referred to as
tag-aware.
Prior to the adoption of 802.1Q VLANs, port-based and MAC-based VLANs were in
common use. These VLANs relied upon a Port VLAN ID (PVID) to forward packets. A
73