Cisco Systems SG50028PK9NA Passive Mode

IP Configuration: RIPv2
How Rip Operates on the Device
Cisco Small Business 200, 300 and 500 Series Managed Switch Administration Guide (Internal Version) 381
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It is your responsibility to set the offset for each interface (1 by default).
The following illustrates the configuration of the metric offset for various
interfaces, based on port speed.
Configuring the Offset (Based on Port Speed)
Router rD can send data to rA via rB or rC. Since rC only supports Fast Ethernet
(FE) ports, and rB supports Gigabit Ethernet (GE) ports, the path cost from router
rD to router rA is higher via router rC (additional 4 to the cost path) as opposed to
the path via router rB (additional 2 to the cost path), Therefore, forwarding traffic
via routing rB is preferred. To achieve this, you configure a different offset (metric
value) on each interface based on its line speed.
See Offset Configuration for more information.
Passive Mode
Transmission of routing update messages over a specific IP interface can be
disabled. In this case, the router is passive, and only receives the updated RIP
information on this interface. By default, transmission of routing updates on an IP
interface is enabled.