LP2XXX Series/LS2200 Switching Configuration Notes

In version 5.1 of LANplex 2XXX (LP2XXX) series and LinkSwitch (LS2200) Switching or Extended Switching software, certain restrictions apply when operating in Switching mode if the system will be managed via IP.

The LP2XXX and LS2200 system software consists of a Switching Engine and a Routing Engine. This high performance architecture permits the system to switch those frames that can be switched at wire speed. Frames are routed only as required.

Wire speed switching performance in a system that will also route is made possible because of the layering of the Switching and Routing Engines. Immediately on reception it is determined whether a frame can be switched or must be routed. Those frames that can be switched, will be without involving the Routing Engine. Layering the software in this way assures the fastest path for switchable frames, including those frames on different ports that share the same subnets.

The layered, Switching/Routing architecture while optimizing performance for all frames, imposes some configuration requirements. These requirements are common to both Standard Switching and Extended Switching Software.

If the LinkSwitch or LANplex will be switching only and will not be managed via IP, there are no restrictions. The system should begin switching regardless of protocol with no configuration required.

If assigning an IP address to the system for management, an IP address within the subnet or the same IP address must be assigned on all ports. Assigning an IP address to a port defines the IP broadcast domain for frames sourced from the attached segment. Therefore, it is imperative that the IP broadcast domain be consistent across all ports to avoid unintentional filtering of IP broadcasts.

If switching multiple subnets through the switch and IP addresses are assigned for management, an address within all subnets that will be switched must be assigned to all ports. This is a less common configuration since the switch would be traversed multiple times to route between subnets.