Cabletron Systems 2H253-25R - Manual (Page 23)

Overview
Introduction 1-3
When Auto-Negotiation is supported at both ends of a link, the two devices dynamically adjust to
full or half duplex operation based on the maximum capability that can be reached between the
two devices. If the device connected to the 2H253-25R cannot auto-negotiate, the 2H253-25R
operates according to the capabilities of the other device.
1.1.3 Runtime IP Address Discovery
This feature enables the 2H253-25R device to automatically accept an IP address from a Boot
Strap Protocol (BootP) server on the network without requiring a user to enter an IP address
through Local Management.
When the device is connected to the network and powered up, Runtime IP Address Discovery
(RAD) checks the device for an IP address. If one has not yet been assigned (device IP address set
to 0.0.0.0), RAD checks to see if any of the device interfaces have a link. If so, RAD sends out
Reverse Address Resolution Protocol (RARP) and BootP requests to obtain an IP address from a
BootP server on the network.
The RAD requests start at an interval of 1 per second. The interval then doubles after every
transmission until an interval of 300 seconds is reached. At this point, the interval remains at 300
seconds. The RAD requests continue until an IP address is received from a RARP or BootP server,
or an IP address is entered using Local Management.
1.1.4 Full Duplex Switched Ethernet
Each switched Fast Ethernet port on the 2H253-25R supports 10/100 Mbps operation, and can
operate in Full Duplex Switched Ethernet (FDSE) mode. FDSE enables each port to provide up to
200 Mbps of bandwidth to connected devices that support FDSE.
1.1.5 SmartTrunk
Traditional 802.1D Spanning Tree Bridges only allow one active data path between any two
switches; all other parallel data paths are in Standby or Blocking mode. If one interface or path
should fail, then the other interface automatically comes out of Blocking mode and forwards all of
the traffic. This is fine for redundancy purposes. However, it is not the most efficient use of
resources.
NOTE
The 2H253-25R will reboot after RAD is successful.