Installation guide

AT-S39 Version 3.0.1 Management Software Release Notes
PN 613-50389-00 Rev A 10 Allied Telesyn, Inc.
• Detection of Denial of Service Attacks
The management software can detect excessive amounts of management packets,
which can be an indication of a denial of service attack. The switch responds by
displaying the following message on the console port:
ATTENTION: Switch is receiving unusual volume of Management traffic.
Possible DENIAL OF SERVICE ATTACK .... Please check you network.”
A switch experiencing a denial of service attack will continue to forward/switch regular
Ethernet traffic, but it will not respond to any management packets. Consequently, the
switch cannot be managed until the attack has ceased or been stopped.
• Reset and Power Cycle Times
Loading the AT-S39 firmware by the switch after a reset or a power cycle now takes
between 30 to 40 seconds to complete.
• SET SWITCH PORT Command
You can set only one parameter at a time with the SET SWITCH PORT command.
• VLANs
The following changes have been made to VLANs:
- The name of the default VLAN has been changed from “Default VLAN” to
“Default_VLAN”.
- You can remove an untagged port from the Default_VLAN without assigning it as an
untagged port of another VLAN.
• GBIC Ports 25 and 26 in the AT-8024GB Switch
Assigning Port 25 or 26 on an AT-8024GB switch to a VLAN when no GBIC module is
installed can result in an incorrect PVID value being assigned to the port. For this reason,
you should assign these ports to a VLAN only when a GBIC module is installed.
•IGMP
The AT-S39 software will not recognize a specific IGMP query from a multicast router. It
will not flood the packet and it will not add the port receiving the query to the multicast
router port list. However, the software does recognize general IGMP queries. Since most
IGMP queries from multicast routers are general queries, this should not effect IGMP
operation on the switch.
•Flow Control
The flow control option is displayed as active when a port is set to half-duplex. However,
changing the flow control setting has no effect when a port is operating in half duplex.
Flow control applies only when a port is operating in full-duplex.