You can deploy a J-series router with multiport uPIMs in branch offices as an access or desktop switch with integrated routing capability, thus eliminating intermediate access switch devices from your topology. The Gigabit Ethernet uPIM provides Ethernet switching while the Routing Engine provides routing functionality, enabling you to use a single chassis to provide routing, access switching, and WAN interfaces.
You can set a multiport uPIM to either of two modes of operation: routing (the default) or switching. Routed traffic is forwarded from any port of the Gigabit Ethernet uPIM to the WAN interface. Switched traffic is forwarded from one port of the Gigabit Ethernet uPIM to another port on the same Gigabit Ethernet uPIM. Switched traffic is not forwarded from a port on one uPIM to a port on a different uPIM.
In routing mode, the multiport uPIM has the same configuration options as any other Gigabit Ethernet interface. To configure uPIM Gigabit Ethernet interfaces in routing mode, see Configuring Gigabit Ethernet Interfaces with Quick Configuration and Configuring Network Interfaces with a Configuration Editor.
In switching mode, the uPIM appears in the list of interfaces as a single interface which is the first interface on the uPIM, for example ge-2/0/0. You can optionally configure each uPIM port only for autonegotiation, speed, and duplex mode. A uPIM in switching mode can perform the following functions:
Gigabit Ethernet uPIMs in switching mode have the following limitations: