Dell POWEREDGE M1000E - Manual (Page 84)

66 Dell Converged Enhanced Ethernet Administrator’s Guide
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Link aggregation overview
7
On each port, link aggregation control:
• Maintains configuration information to control port aggregation.
• Exchanges configuration information with other devices to form LAGs.
• Attaches ports to and detaches ports from the aggregator when they join or leave a LAG.
• Enables or disables an aggregator’s frame collection and distribution functions.
Each link in the Dell FCoE hardware can be associated with a LAG; a link cannot be associated with
more than one LAG. The process of adding and removing links to and from a LAG is controlled
either statically, dynamically, or through LACP.
Each LAG consists of the following components:
• A MAC address that is different from the MAC addresses of the LAG’s individual member links.
• An interface index for each link to identify the link to neighboring devices.
• An administrative key for each link. Only links having the same administrative key value can be
aggregated into a LAG. On each link configured to use LACP, LACP automatically configures an
administrative key value equal to the port-channel identification number.
Figure 4 and Figure 5 show typical IP SAN configurations using LAGs. In a data center the Dell
M8428-k switch fits into the top-of-the-rack use case where all the servers in a rack are connected
to the Dell M8428-k switch through Twinax copper or optical fiber cable. The database server layer
connects to the top-of-the-rack Dell M8428-k switch which is located in the network access layer.
The Dell M8428-k switch connects to Layer 2/Layer 3 aggregation routers which provide access
into the existing LAN. This connectivity is formed in a standard V-design or square-design. Both
designs use the LAG as the uplink to provide redundancy and improved bandwidth.