Brocade Communications Systems 53-1002163-02 manual

6 Ingress VLAN filtering

•Admit VLAN tagged and untagged frames—All tagged and untagged frames would be processed as follows:

-All untagged frames are classified into native VLANs.

-All frames egressing are untagged for the native VLANs.

-Any tagged frames coming with a VLAN tag equal to the configured native VLAN are processed.

-For ingress and egress, non-native VLAN tagged frames are processed according to the allowed VLAN user specifications. This is called converged mode.

NOTE

Ingress VLAN filtering is enabled by default on all Layer 2 interfaces. This ensures that VLANs are filtered on the incoming port (depending on the user configuration).

Figure 4 displays the frame processing logic for an incoming frame.

FIGURE 4 Ingress VLAN filtering

Incoming frame on an interface

Is the port	Yes	Is the VLAN ID	No
a trunk?		an allowed VLAN?

No

Drop frame

Yes

		Assign the frame to the
No	Is the port an	VLAN present in the VLAN ID
		field of the Ethernet header
	access interface?

Drop frame

Yes

Does the frame match any

of the configured VLAN classifiers

(MAC address based and

protocol based)?

Yes

Assign the

frame to the

classified VLAN

No

Assign the

frame to the

configured PVID

There are important facts you should know about Ingress VLAN filtering:

•Ingress VLAN filtering is based on port VLAN membership.

•Port VLAN membership is configured through the CEE CLI.

•Dynamic VLAN registration is not supported.

•The Brocade FCoE hardware does VLAN filtering at both the ingress and egress ports.

•The VLAN filtering behavior on logical Layer 2 interfaces such as LAG interfaces is the same as on port interfaces.

•The VLAN filtering database (FDB) determines the forwarding of an incoming frame.

46	Converged Enhanced Ethernet Administrator’s Guide
	53-1002163-02