User guide

September 2009
Page 12 of 79 OmniSwitch 6400/6850/6855/9000/9000E—Release 6.4.2.R01
New Feature/Enhancement Descriptions
10Km Stacking
The OS6855-U24X supports stacking a maximum of four chassis into a virtual chassis using SFP+
fiber transceivers or directly attached copper SFP+ cables . A distance of up to 10Km is supported
using the iSFP-10G-LR fiber transceiver.
802.1x Radius-down Fail-Open
Allows users to be moved to a specified profile when the RADIUS server is not available. This feature
is supported for 802.1x and MAC-based authentication, but not for users being authenticated by
captive-portal.
Users classified through the auth-server-down policy are flagged for re-authentication when the
authentication server becomes reachable.
DDM - Digital Diagnostic Monitoring
Digital Diagnostics Monitoring allows an OmniSwitch to monitor the status of an SFP/XFP by reading
the information contained on the transceiver’s EEPROM. The transceiver can display Actual, Warning-
Low, Warning-High, Alarm-Low and Alarm-High for the following:
• Temperature
• Supply Voltage
• Current
• Output Power
• Input Power
Traps can be enabled if any of these above values crosses the pre-defined low or high thresholds of the
transceiver.
Note: Not all transceivers support DDM, refer to the Transceivers Guide for additional DDM
information.
DHCP Snooping Option 82 – Port-based format
Enhances the Option 82 capability by allowing the ‘interface alias’ to be inserted into the Circuit ID
and Remote ID suboptions of the Option-82 field
Ethernet OAM 802.3ah – Ethernet First Mile (EFM)
IEEE 802.3ah, defining Ethernet in the access networks that connects subscribers to their immediate
service provider. EFM, EFM-OAM and LINKOAM refers to IEEE 802.3ah standard.
LINK OAM (operation, administration, and maintenance) is a tool which monitors Layer-2 link status
on the network by sending OAM protocol data units (OAMPDUs) between the network devices.
OAMPDUs contain control and status information used to monitor, test and troubleshoot OAM-
enabled links. By enabling LINK OAM on switch ports, network administators can monitor the link-
related issues on the first mile. LINK OAM provides network administrators the ability to monitor link
performance, remote fault detection and remote loopback control.