RuggedCom Welder RS400 用户手册

 

 

VLANs 

RS400 

171 

ROS™  v3.5 

VLAN the frame associated with 

PVID 

PVID 

VID in the tag 

Frame dropped due to its 
tagged/untagged format 

No No No 

Frame dropped, if associated with VLAN 
not configured (or learned) in the switch 

N/A N/A Yes 

Frame dropped, if ingress port is not a 
member of the VLAN the frame 
associated with 

N/A N/A No 

 

Egress Rules 

These are the VLAN egress rules, i.e. the rules applied to all frames when they are transmitted 
by the switch: 

Edge 

N/A (frame is dropped) 

Trunk 

According to the egress 

port’s “PVID Format” 

parameter 

Tagged dropped 

 

 

Each VLAN can be configured to exclude ports from membership in the VLAN.  

The native operation mode for an IEEE 802.1Q compliant switch is VLAN-aware. Even if a 
specific network architecture doesn’t use VLANs, ROS

TM

 default VLAN settings allow the switch 

still to operate in a VLAN-aware mode while providing functionality required for almost any 
network application. However, the IEEE 802.1Q standard defines a set of rules that must be 
followed by all VLAN-aware switches, for example: 

•  Valid VID range is 1 to 4094 (VID=0 and VID=4095 are invalid) 

•  Each frame ingressing a VLAN-aware switch is associated with a valid VID  

•  Each frame egressing a VLAN-aware switch is either untagged or tagged with a valid VID 

(this means priority-tagged frames with VID=0 are never sent out by a VLAN-aware switch) 

It turns out that some applications have requirements conflicting with the IEEE 802.1Q native 
mode of operation (e.g. some applications explicitly require priority-tagged frames to be 
received by end devices).