Redundant Twisted Pair Ports - Allied Telesis AT-9424Ts Installation Manual

Redundant Twisted Pair Ports

The SFP slots 21 through 24 on the AT-9424Ts and AT-9424Ts/XP
Switches are paired with twisted pair ports 21R through 24R, respectively.
The "R" in the twisted pair port numbers on the front faceplates of the units
stands for "Redundant." Here are the guidelines to using these ports and
slots:

Only one port in a pair -- the twisted pair port or the port on the
corresponding SFP module -- can be active at a time.
 The twisted pair port is the active port when its SFP slot is empty, or
when an SFP module is installed but has not established a link to an
end node.
 The twisted pair port automatically changes to the redundant status
mode when an SFP module establishes a link with an end node.

A twisted pair port automatically transitions back to the active status
when the link is lost on the SFP module.
 In nearly all cases, a twisted pair port and an SFP module share the
same configuration settings, including port settings, VLAN
assignments, access control lists, and spanning tree.
 An exception to the shared settings is port speed. If you disable Auto-
Negotiation on a twisted pair port and set the speed and duplex mode
manually, the speed reverts to Auto-Negotiation when an SFP module
establishes a link with an end node.
Note
These guidelines do not apply to the XFP slots on the AT-9424Ts/XP
and AT-9448Ts/XP Switches.
AT-9400Ts Stack Installation Guide
23