Distributed Link Aggregation (Dla) - 3Com 5500-SI Configuration Manual

674 A D: 3C XRN
PPENDIX OM
Distributed Link
Aggregation (DLA)
Switch units within the Distributed Fabric provide the same router interfaces and
mirror each other's routing tables. This allows each unit to keep the routing local
to the unit for locally connected hosts and devices.
In the example shown in Figure 178, there is a single logical router across the XRN
Distributed Fabric with router interfaces (R1, R2, and R3) shared by both units.
If there is a loss of a unit in an XRN Distributed Fabric it does not affect routing
provided you are using Distributed Link Aggregation or the devices in the wiring
closet are multihomed.
DRR is an XRN-specific implementation that only operates on XRN within the
Distributed Fabric. However it will interoperate with other routers outside of the
XRN Distributed Fabric.
Figure 178 Network Example illustrating Distributed Resilient Routing
VLAN1 VLAN 2
XRN Distributed
XRN Distributed
DLA ensures that all member ports of an aggregated link distribute the traffic flow
across the Distributed Fabric. This provides resilience and enhanced performance.
Failure in one of the member links in the Aggregated Link will not affect
communication to the Distributed Fabric as traffic will be forwarded using the
remaining member links. Details of the the number of member links and
Aggregated Links supported by the Switches in a Distributed Fabric are listed in
Table 691.
VLAN 1 VLAN 3
Fabric
R1 R2 R3
R1 R2 R3
Fabric
R1 R2 R3
R1 R2 R3
VLAN 2 VLAN 3
Switch 5500 units
Core Switches