User manual

8.58. CFI: Canonical Format Indicator is always set to zero for Ethernet switches. CFI is used for

compatibility between Ethernet type network and Token Ring type network. 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.

8.59. When you enable the first VLAN Packets and set the VID, User Priority, and CFI, then all the

incoming packets with the TA’s IP address and the same VID will be accept by the TA. If the

incoming packets with TA’s IP address but different VID then the packets will be discard by

the TA. The Other incoming packets with different IP address will go through the WAN port to

the LAN port.

8.60. NAT VLAN Setting: When VS211 is set in embedded NAT mode, the TA will filter out the

wrong incoming packets. You can separate the other devices connected behind the

embedded NAT into 4 VLAN groups by assigning different VID for these 4 groups. The VS211

will check the VID of the incoming packets from ADSL modem. If the packet is not with the

VS211 IP address and the right VID, or the VID is not of of these 4 VIDs you set, then the

packets will be discarded by the VS211.