PLANET ISW-504PS - Manual (Page 54)

User’s Manual
4.5.2 VLAN Per Port Setting
The Industrial PoE Switch inserts or removes a tag of frame if Tag / UnTag function is enabled. The operation is illustrated
as follows. As shown in
Figure 4-30 and description on Table 4-12.
Understand nomenclature of the 802.1Q VLAN aware Switch
Tagging and Untagging
Every port on an 802.1Q compliant switch can be configured as tagging or untagging.
。 Tagging: Ports with tagging enabled will put the VID number, priority and other VLAN information into the header of
all packets that flow into those ports. If a packet has previously been tagged, the port will not alter the packet, thus
keeping the VLAN information intact. The VLAN information in the tag can then be used by other 802.1Q compliant
devices on the network to make packet-forwarding decisions.
。 Untagging: Ports with untagging enabled will strip the 802.1Q tag from all packets that flow into those ports. If the
packet doesn't have an 802.1Q VLAN tag, the port will not alter the packet. Thus, all packets received by and
forwarded by an untagging port will have no 802.1Q VLAN information. (Remember that the PVID is only used
internally within the Switch). Untagging is used to send packets from an 802.1Q-compliant network device to a
non-compliant network device.
Frame Income
Frame Leave
Income Frame is tagged Income Frame is untagged
Leave port is tagged Frame remains tagged
Tag is inserted
(Tag=PVID or Original VID be remained)
Leave port is untagged Tag is removed
Frame remain untagged
(Tag=PVID be removed)
Figure 4-30 VLAN Per port setting screen
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