Netgear GS748Tv4 GS748Tv4 Software Administration Manual - Page 45

Denial of Service, Refresh, SIP=DIP, First Fragment

Page 45 highlights

GS748T Smart Switch Software Administration Manual The SNTP Server Status table displays status information about the SNTP servers configured on your switch. The following table describes the SNTP Global Status fields. Field Description Address Last Update Time Last Attempt Time Specifies all the existing Server Addresses. If no Server configuration exists, a message saying "No SNTP server exists" flashes on the screen. Specifies the local date and time (UTC) that the response from this server was used to update the system clock. Specifies the local date and time (UTC) that this SNTP server was last queried. Last Attempt Status Specifies the status of the last SNTP request to this server. If no packet has been received from this server, a status of Other is displayed: • Other: None of the following enumeration values. • Success: The SNTP operation was successful and the system time was updated. • Request Timed Out: A directed SNTP request timed out without receiving a response from the SNTP server. • Bad Date Encoded: The time provided by the SNTP server is not valid. • Version Not Supported: The SNTP version supported by the server is not compatible with the version supported by the client. • Server Unsynchronized: The SNTP server is not synchronized with its peers. This is indicated via the 'leap indicator' field on the SNTP message. • Server Kiss Of Death: The SNTP server indicated that no further queries were to be sent to this server. This is indicated by a stratum field equal to 0 in a message received from a server. Requests Failed Requests Specifies the number of SNTP requests made to this server since last agent reboot. Specifies the number of failed SNTP requests made to this server since last reboot. Click Refresh to refresh the page with the most current data from the switch. Denial of Service Use the Denial of Service (DoS) page to configure DoS control. The GS748T Smart Switch software provides support for classifying and blocking specific types of DoS attacks. You can configure your system to monitor and block the following types of attacks: • SIP=DIP: Source IP address = Destination IP address. Enable or disable this option by selecting the corresponding line on the radio button. Enabling SIP=DIP DoS prevention causes the switch to drop packets that have a source IP address equal to the destination IP address. The factory default is disabled. • First Fragment: IP Fragment Offset = 1. Enable or disable this option by selecting the corresponding line on the radio button. Enabling First Fragment DoS prevention causes the switch to drop packets that have an IP fragment offset equal to 1. The factory default is disabled. Chapter 2: Configuring System Information | 45

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Chapter 2:
Configuring System Information
|
45
GS748T Smart Switch Software Administration Manual
The SNTP Server Status table displays status information about the SNTP servers
configured on your switch. The following table describes the SNTP Global Status fields.
Click
Refresh
to refresh the page with the most current data from the switch.
Denial of Service
Use the Denial of Service (DoS) page to configure DoS control. The GS748T Smart Switch
software provides support for classifying and blocking specific types of DoS attacks. You can
configure your system to monitor and block the following types of attacks:
SIP=DIP
: Source IP address = Destination IP address. Enable or disable this option by
selecting the corresponding line on the radio button. Enabling SIP=DIP DoS prevention
causes the switch to drop packets that have a source IP address equal to the destination
IP address. The factory default is disabled.
First Fragment
: IP Fragment Offset = 1. Enable or disable this option by selecting the
corresponding line on the radio button. Enabling First Fragment DoS prevention causes
the switch to drop packets that have an IP fragment offset equal to 1. The factory default
is disabled.
Field
Description
Address
Specifies all the existing Server Addresses. If no Server configuration exists, a
message saying “No SNTP server exists” flashes on the screen.
Last Update Time
Specifies the local date and time (UTC) that the response from this server was
used to update the system clock.
Last Attempt Time
Specifies the local date and time (UTC) that this SNTP server was last queried.
Last Attempt Status
Specifies the status of the last SNTP request to this server. If no packet has been
received from this server, a status of Other is displayed:
Other
: None of the following enumeration values.
Success
: The SNTP operation was successful and the system time was
updated.
Request Timed Out
: A directed SNTP request timed out without receiving a
response from the SNTP server.
Bad Date Encoded
: The time provided by the SNTP server is not valid.
Version Not Supported
: The SNTP version supported by the server is not
compatible with the version supported by the client.
Server Unsynchronized
: The SNTP server is not synchronized with its
peers. This is indicated via the 'leap indicator' field on the SNTP message.
Server Kiss Of Death
: The SNTP server indicated that no further queries
were to be sent to this server. This is indicated by a stratum field equal to 0 in
a message received from a server.
Requests
Specifies the number of SNTP requests made to this server since last agent
reboot.
Failed Requests
Specifies the number of failed SNTP requests made to this server since last
reboot.