Nortel Networks 1000BASE-SX, 1000ASE-XD, 1000BASE-LX, 1000BASE-ZX manual

Models: 1000ASE-XD 1000BASE-ZX 1000BASE-SX 1000BASE-LX

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•Untagged member—a port that has been configured as an untagged member of a specific VLAN. When an untagged frame exits the switch through an untagged member port, the frame header remains unchanged. When a tagged frame exits the switch through an untagged member port, the tag is stripped and the tagged frame is changed to an untagged frame.

56 Chapter 2 Network configuration

Untagged member—a port that has been configured as an untagged member of a specific VLAN. When an untagged frame exits the switch through an untagged member port, the frame header remains unchanged. When a tagged frame exits the switch through an untagged member port, the tag is stripped and the tagged frame is changed to an untagged frame.

Tagged member—a port that has been configured as a member of a specific VLAN. When an untagged frame exits the switch through a tagged member port, the frame header is modified to include the 32-bit tag associated with the PVID. When a tagged frame exits the switch through a tagged member port, the frame header remains unchanged (original VID remains).

User priority—a three-bit field in the header of a tagged frame. The field is interpreted as a binary number, therefore has a value of 0 - 7. This field allows the tagged frame to carry the user-priority across bridged LANs where the individual LAN segments may be unable to signal priority information.

Port priority—the priority level assigned to untagged frames received on a port. This value becomes the user priority for the frame. Tagged packets get their user priority from the value contained in the 802.1Q frame header.

Unregistered packet—a tagged frame that contains a VID where the receiving port is not a member of that VLAN.

The default configuration settings for BayStack 420 switches have all ports set as untagged members of VLAN 1 with all ports configured as PVID = 1. Every VLAN is assigned a unique VLAN identifier (VID) that distinguishes it from all other VLANs. In the default configuration example shown in Figure 12, all incoming packets are assigned to VLAN 1 by the default port VLAN identifier (PVID =1). Untagged packets enter and leave the switch unchanged.

209418-A

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Nortel Networks 1000BASE-SX, 1000ASE-XD, 1000BASE-LX, 1000BASE-ZX manual