***Most of this document is the same as “Cisco DCI Design & Implementation“, so those parts are eliminated.***
DCI Considerations
Figure 1 shows the main considerations when deploying a DCI solution:
- Layer 3 interconnect (typically over an existing enterprise IP core)
- Layer 2 interconnect
- SAN interconnect
DCI Transport Options
Business Continuance: High-Availability Clusters
Some network communication between members of high-availability clusters 1 requires some clusters to be Layer 2 (Figure 3):
- Private interprocess communication (such as heartbeat and database replication) used to maintain and control the state of the active node
- Public communication (virtual IP of the cluster)
DCI LAN Extension for VMware VMotion
MEC is the easiest solution with which to deploy redundant Layer 2 links. It can be implemented with either the Cisco Nexus 7000 Series vPC or the Cisco Catalyst 6500 Series VSS. Cisco specifically recommends MEC for metropolitan area network (MAN) distances between remote sites where the interconnections between physical links are provided using dedicated fibers. This technology provides high availability with all redundant active links as MECs, as well as failover times of less than a second. It can be deployed for point-to-point connectivity between two data centers from the aggregation layer.
