Foundry NetIron M2404C and M2404F Metro Access Switches
Configuring Interfaces (Rev. 03)
Link Aggregation Groups (LAG)
© 2008 Foundry Networks, Inc.
Page 25 of 57
Link Aggregation Groups (LAG)
Link Aggregation Groups (LAGs), also known as trunks, provide increased bandwidth and high
reliability while saving the cost of upgrading the hardware. By combining several interfaces into
one logical link, LAGs offer network channels tailored to need, filling the gaps between 10 Mbps,
100 Mbps and 1 Gbps with intermediate bandwidth values. LAGs also enable bandwidths beyond
the current 1 Gbps limit by aggregating multiple Giga ports (see
Figure 2
for example).
Figure 2: Four Ports Combined into a Link Aggregation Group
The Link Aggregation Control Protocol (LACP) ensures smooth and steady traffic flow by
automating the configuration, re-configuration and maintenance of aggregated links. The LACP
feature, available on all switches, dynamically adapts aggregated links to changes in traffic
conditions. Load sharing is maintained and automatically readjusted if a failure or recovery from
failure occurs in any of the links that participate in a dynamic LAG.
The application software supports both static and dynamic LAGs. Static and dynamic LAGs can
exist simultaneously on the same device.
NOTE
Link Aggregation Groups are not supported on the M2404 enhanced uplink ports.