Forbidden Ports List; Vlan-Aware And Vlan-Unaware Modes - Siemens RUGGEDCOM ROS v4.3 User Manual

Chapter 5
Setup and Configuration
a
Frame Received
VLAN ID associated with the frame
Frame dropped due to its tagged/untagged format
Frame dropped if the ingress port is not a member of the VLAN the
frame is associated with and ingress filtering is enabled
a
Does not depend on the ingress port's VLAN configuration parameters.
Egress rules are applied as follows to all frames when they are transmitted by the switch.
Egress Port Type
Edge
Trunk
Section 5.1.1.6

Forbidden Ports List

Each VLAN can be configured to exclude ports from membership in the VLAN using the forbidden ports list. For
more information, refer to
Section 5.1.1.7

VLAN-Aware and VLAN-Unaware Modes

The native operation mode for an IEEE 802.1Q compliant switch is VLAN-aware. Even if a specific network
architecture does not use VLANs, RUGGEDCOM ROS's default VLAN settings allow the switch to still 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:
• Valid VIDs are within the range of 1 to 4094. VIDs equal to 0 or 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. Priority-tagged frames
with an invalid VID will never sent out by a VLAN-aware switch.
NOTE
Some applications have requirements conflicting with IEEE 802.Q1 native mode of operation. For
example, some applications explicitly require priority-tagged frames to be received by end devices.
To avoid conflicts and provide full compatibility with legacy (VLAN-unaware) devices, RUGGEDCOM
ROS can be configured to work in VLAN-unaware mode.
In that mode:
• Frames ingressing a VLAN-unaware device are not associated with any VLAN
• Frames egressing a VLAN-unaware device are sent out unmodified (i.e. in the same untagged,
802.1Q-tagged or priority-tagged format as they were received)
136
On Egress Port's Native VLAN
According to the egress port's
PVID Format parameter
Section 5.1.5.2, "Adding a Static VLAN"
Priority Tagged
Untagged
(VID = 0)
PVID
No
On Other VLAN
Port Is a Member Of the VLAN
Dropped
Tagged
.
RUGGEDCOM ROS
User Guide
Tagged (Valid VID)
PVID VID in the Tag
No No
Yes
Port Is Not a Member
Of the VLAN
Dropped
Forbidden Ports List