Juniper Networks IDP SERIES IDP250 - Manual (Page 47)

Connecting Devices That Support Auto-MDIX
If you are connecting devices that support auto-MDIX (medium dependent interface
crossover), you can use either straight-through or crossover cables because auto-MDIX
negotiates the correct connection.
NOTE: IDP75, IDP250, IDP800, and IDP8200 support auto-MDIX.
Connecting Devices That Do Not Support Auto-MDIX
For connections to a firewall or server, use a crossover cable.
For connections to a switch or hub, use a straight-through cable.
NOTE: Conventionally, crossover cables have an orange outer jacket. If you
are not sure if your Cat 5 cable is a crossover or straight-through cable, lay
the two ends side-by-side and observe the order of the wire colors. If the
colors are in the same order, it is a straight-through cable; otherwise, it is a
crossover cable.
Connecting Devices to Support Internal Bypass
When internal bypass activates, it physically connects the pair of traffic interfaces to
each other with a crossover connection.
If the device does not support auto-MDIX, take special care to choose the right cables.
Suppose you plan to place the IDP Series appliance inline between a firewall and a switch.
First, take note of the correct cable choice for a direct connection between the firewall
and switch. Would you use a straight-through cable or a cross-over cable?
If the two devices would be connected with a straight-through cable, then use a crossover
cable between the firewall and the IDP Series appliance and a straight-through cable
between the IDP Series appliance and the switch. When internal bypass activates and
crosses-over the connection between the IDP Series traffic interface pair, the connection
between the firewall and the switch will flow as if through a straight-through cable.
If the two devices would be connected with a cross-over cable, then use two
straight-through cables. When internal bypass activates, this will have the result of
creating one, long cross-over cable connecting the devices.
Connecting and Disconnecting Fiber Cables
The following procedures describe how to connect and remove a Gigabit Ethernet cable
to and from the transceiver.
35 Copyright © 2012, Juniper Networks, Inc.
Chapter 6: Connecting the IDP Traffic Interfaces to Your Network and Verifying Traffic Flow