Configure Ethernet interfaces
Digi TransPort User Guide
156
Metric
The connected metric of an interface. Changing this value will alter the metric of dynamic
routes created automatically for this interface. The default metric of a connected interface is
1. By allowing the interface to have a higher value (lower priority), static routes can take
preference to interface generated dynamic routes. For normal operation, leave this value
unchanged.
MTU
The Maximum Transmit Unit for the specified interface. The default value is 0 meaning that
the MTU will either be 1504 (for routers using a Kendin Ethernet device) or 1500 (for non-
Kendin devices). The non-zero, values must be greater than 128 and not more than the default
value. Values must also be multiples of 4 and the router will automatically adjust invalid
values entered by the user. So, if the MTU is set to 1000, the largest IP packet that the router
will send is 1000 bytes.
Enable auto-negotiation
Allows the router and the other Ethernet device it is connected to, to auto-negotiate the
speed and duplex of the Ethernet connection.
Speed (currently 100Base-T)
Selects either of the
10Base-T
,
100Base-T
, or
Auto
modes. The currently selected mode is
shown in brackets after the parameter name.
Note, enabling
Auto-negotiation
and manually setting the speed will only allow the selected
speed to be negotiated.
Duplex
Selects either of
Full Duplex
,
Half Duplex
or
Auto
mode. Enabling
Auto-negotiation
and
manually setting the Duplex will only allow the selected Duplex mode to be negotiated.
Max Rx rate
On models with multiple Ethernet interfaces, this parameter specifies a maximum data rate in
Kbps that the router receives on this interface. This may be useful in applications where
separate Ethernet interfaces are allocated to separate LANs and it is necessary to prioritize
traffic from one LAN over another.
Max Tx rate
On models with multiple Ethernet interfaces, this parameter specifies a maximum data rate in
kbps that the router will transmit on this interface. This may be useful in applications where
separate Ethernet interfaces are allocated to separate LANs and it is necessary to prioritize
traffic from one LAN over another.
TCP transmit buffer size
When set to a non-zero value, this parameter sets the TCP buffer size of transmitted packets in
bytes. This is useful for slow / lossy connections such as satellite. Setting this buffer to a low
value will prevent the amount of unacknowledged data from getting too high. If retransmits
are required, a smaller TX buffer helps prevent retransmits flooding the connection.
