Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 535)

SPAN in logical chassis cluster guidelines and limitations
In addition to the standard SPAN limitations, note the following guidelines and limitations for SPAN in
logical chassis cluster:
• The Brocade VDX 6720 is not supported as SPAN source node in logical chassis cluster but it can
act as a destination node.
• The Brocade VDX 6740, VDX 6740T, VDX 6740T-1G, and VDX 6730 are supported as both source
and destination nodes for SPAN in logical chassis cluster.
• SPAN in logical chassis cluster supports up to 512 sessions.
• For SPAN with the destination port residing on a remote node, the show span path session
session-number command shows the path taken by the mirrored packets in the cluster.
RSPAN guidelines and limitations
The following configurations and restrictions for RSPAN should be kept in mind.
Basic considerations
• All participating switches must be connected by Layer 2 trunks.
• Inter-Switch Link (ISL) mirroring is not supported on RSPAN.
• The source and destination ports cannot both be TRILL (ISL) ports.
• RSPAN supports multi-hop.
• RSPAN can support both the fabric cluster and logical chassis cluster modes. However, using
RSPAN in logical chassis cluster mode uses unnecessary ISL bandwidth because it floods the traffic
on the ISL as well as the trunk port.
• If the source port is not Layer 2 and untagged traffic is mirrored, it will be dropped for RSPAN
because untagged and unclassified traffic is dropped on an ISL trunk.
• On the Brocade VDX 6740 series platforms, if source port is in unknown mode, that is neither Layer
2 nor Layer 3, the packets are dropped and are not mirrored.
• Ethernet Pause frames are not mirrored.
VLAN considerations
• Before you configure an RSPAN session, you must create the RSPAN VLAN.
• A native VLAN cannot be made the RSPAN VLAN.
• The VLAN used for RSPAN should not be used for other purposes; furthermore, if the VLAN has
ports as its members, it cannot be made an RSPAN VLAN. Only when the session is deconfigured,
and the VLAN is deleted as an RSPAN VLAN, should the VLAN number be used for another
purpose.
• You can configure any VLAN as an RSPAN VLAN as long as all participating network devices
support the configuration of RSPAN VLANs and you use the same RSPAN VLAN for each RSPAN
session in all participating network devices.
• You must configure the RSPAN VLANs on all source, intermediate, and destination network devices.
• Do not configure any ports in an RSPAN VLAN except the ports selected to carry RSPAN traffic.
However, all configurations are allowed on the RSPAN destination port.
• The vlan-id of the packets marked for RSPAN will change to the RSPAN vlan-id.
• Access ports can be added to an RSPAN VLAN as destination ports.
• MAC address learning is disabled in the RSPAN VLAN.
SPAN in logical chassis cluster guidelines and limitations
Network OS Administrator’s Guide 535
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