SMC Networks 7724M/VSW - annexe 1, Manual

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CLI Management Guide
TigerAccess™ EE
244 SMC7824M/VSW
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Community : Community ports communicate among themselves and with their pro-
miscuous ports. These interfaces are separated at Layer 2 from all other interfaces in
other communities or isolated ports within their PVLAN.
The difference between Private VLAN and Private VLAN edge is that PVLAN edge guar-
antees security for the ports in a VLAN using protected port and PVLAN guarantees port
security by creating sub-VLAN with the three types (Promiscuous, Isolation, and Commu-
nity). And because PVLAN edge can work on local switch, the isolation between two
switches is impossible.
The switch provides Private VLAN function like Private VLAN edge of Cisco product. Be-
cause it does not create any sub-VLAN, port security is provided by port isolation. If you
want to configure Private VLAN on the switch switch, refer to Port Isolation configuration.
8.1.10.1 Shared VLAN
This chapter is only for Layer 2 switch operation. Because there is no routing information
in Layer 2 switch, each VLAN cannot communicate. Especially, the uplink port should re-
ceive packets from all VLANs. Therefore when you configure the switch as Layer 2 switch,
the uplink ports must be included in all VLANs.
default br2 br3
br4 br5
Outer Network
Uplink Port
SWITCH(bridge)# show vlan
u: untagged port, t: tagged port
-----------------------------------------------------------------
| 1 2 3 4
Name( VID| FID) |123456789012345678901234567890123456789012
-----------------------------------------------------------------
default( 1| 1) |u...uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
br2( 2| 2) |.u.....................u..................
br3( 3| 3) |..u....................u..................
br4( 4| 4) |...u...................u..................
br5( 5| 5) |....u..................u..................
SWITCH(bridge)#
Fig. 8.5 Outgoing Packets under Layer 2 Shared VLAN Environment
As above configuration with untagged packet, if an untagged packet comes into port 1, it
is added with
tag 1 for PVID 1. And the uplink port 24 is also included in the default
VLAN; it can transmit to port 24.
However a problem can be occurred for coming down untagged packets to uplink ports. If
an untagged packet comes to uplink ports from outer network, the system does not know
which PVID it has and where should it forward.