Brocade Network OS Administrator’s Guide v4.1.1 User Manual
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FIGURE 22 Metro VCS and distributed Ethernet fabrics
In order to connect two distinct VCS Ethernet fabrics between data centers, a third Metro VCS fabric
can be formed, and the distinct local VCS Ethernet fabrics can connect to the Metro VCS fabric by
means of Virtual Link Aggregation (vLAG).
Alternatively, the distinct VCS Ethernet fabrics in the respective data centers can be directly connected
to each other by means of vLAG over xWDM up to a distance of 30 km. Wherever bit-transparency is
not achievable in xWDM equipment, this solution can be successfully deployed for edge-to-edge
interconnectivity (using 10-G vLAG over multiple standard Ethernet links). This deployment is referred
to as "Distributed Ethernet Fabrics using vLAG".
This implementation eliminates the need for the creation of a separate Metro VCS fabric to achieve
local VCS cluster isolation while providing Layer 2 connectivity. In such a deployment, DCB/FCoE
lossless Ethernet traffic is not supported.
NOTE
When a port-channel from a node in one VCS (or on from any standalone switch) spans across multiple
RBridges in other VCS luster, a vLAG is formed on the RBridges in the VCS cluster that are part of the
same port-channel. For Distributed Ethernet Fabrics using vLAG over long distances, only LACP-based
standard port-channels are supported. For details on how to create port-channels and vLAGs, refer to
on page 437.
Supported platforms for Distributed Ethernet Fabrics using vLAG
The following VDX platforms are supported for Distributed Ethernet Fabrics using vLAG:
• Brocade VDX 6720-60
• Brocade VDX 6730-76
• Brocade VDX 6740, 6740T, and 6740T-1G
• Brocade VDX 8770 with the VDX LC48x10G line card
Topology for Distributed Ethernet Fabrics using vLAG
The following is a typical deployment topology that uses Distributed Ethernet Fabrics using vLAG to
interconnect data centers.. A node from the local VCS cluster is connected by means of xWDM to the
nodes in other VCS clusters to form a vLAG. The other VCS cluster could be spanned across two data
centers over standard-distance or long-distance ISLs, as shown below. In this case, the vLAG between
the two data centers provides VCS fabric isolation while providing seamless Layer 2 connectivity; the
first port-channel (Po1) forms the vLAG between VCS1 and VCS2 over long distance through xWDM.
Supported platforms for Distributed Ethernet Fabrics using vLAG
Network OS Administrator’s Guide
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