Owner manual
Table Of Contents
- Contents
- Tables
- Preface
- Section I
- Basic Operations
- Chapter 1
- Starting a Command Line Management Session
- Chapter 2
- Basic Command Line Commands
- Chapter 3
- Basic Switch Commands
- DISABLE DHCPBOOTP
- DISABLE IP REMOTEASSIGN
- DISABLE TELNET
- ENABLE BOOTP
- ENABLE DHCP
- ENABLE IP REMOTEASSIGN
- ENABLE TELNET
- PING
- PURGE IP
- RESET SWITCH
- RESET SYSTEM
- RESTART REBOOT
- RESTART SWITCH
- SET ASYN
- SET IP INTERFACE
- SET IP ROUTE
- SET PASSWORD MANAGER
- SET PASSWORD OPERATOR
- SET SWITCH CONSOLETIMER
- SET SYSTEM
- SET TELNET INSERTNULL
- SET USER PASSWORD
- SHOW ASYN
- SHOW CONFIG DYNAMIC
- SHOW CONFIG INFO
- SHOW DHCPBOOTP
- SHOW IP INTERFACE
- SHOW IP ROUTE
- SHOW SWITCH
- SHOW SYSTEM
- Chapter 4
- Enhanced Stacking Commands
- Chapter 5
- Simple Network Time Protocol (SNTP) Commands
- Chapter 6
- SNMPv2 and SNMPv2c Commands
- Chapter 7
- Port Parameter Commands
- Chapter 8
- Port Statistics Commands
- Chapter 9
- MAC Address Table Commands
- Chapter 10
- Static Port Trunking Commands
- Chapter 11
- LACP Port Trunking Commands
- Chapter 12
- Port Mirroring Commands
- Chapter 13
- Networking Stack
- Section II
- Advanced Operations
- Chapter 14
- File System Commands
- Chapter 15
- File Download and Upload Commands
- Chapter 16
- Event Log and Syslog Server Commands
- Chapter 17
- Classifier Commands
- Chapter 18
- Access Control List Commands
- Chapter 19
- Class of Service (CoS) Commands
- Chapter 20
- Quality of Service (QoS) Commands
- ADD QOS FLOWGROUP
- ADD QOS POLICY
- ADD QOS TRAFFICCLASS
- CREATE QOS FLOWGROUP
- CREATE QOS POLICY
- CREATE QOS TRAFFICCLASS
- DELETE QOS FLOWGROUP
- DELETE QOS POLICY
- DELETE QOS TRAFFICCLASS
- DESTROY QOS FLOWGROUP
- DESTROY QOS POLICY
- DESTROY QOS TRAFFICCLASS
- PURGE QOS
- SET QOS FLOWGROUP
- SET QOS POLICY
- SET QOS PORT
- SET QOS TRAFFICCLASS
- SHOW QOS FLOWGROUP
- SHOW QOS POLICY
- SHOW QOS TRAFFICCLASS
- Chapter 21
- Denial of Service Defense Commands
- Section III
- IGMP Snooping, MLD Snooping, and RRP Snooping
- Chapter 22
- IGMP Snooping Commands
- Chapter 23
- MLD Snooping Commands
- Chapter 24
- RRP Snooping Commands
- Section IV
- SNMPv3
- Chapter 25
- SNMPv3 Commands
- ADD SNMPV3 USER
- CLEAR SNMPV3 ACCESS
- CLEAR SNMPV3 COMMUNITY
- CLEAR SNMPV3 NOTIFY
- CLEAR SNMPV3 TARGETADDR
- CLEAR SNMPV3 VIEW
- CREATE SNMPV3 ACCESS
- CREATE SNMPV3 COMMUNITY
- CREATE SNMPV3 GROUP
- CREATE SNMPV3 NOTIFY
- CREATE SNMPV3 TARGETADDR
- CREATE SNMPV3 TARGETPARAMS
- CREATE SNMPV3 VIEW
- DELETE SNMPV3 USER
- DESTROY SNMPv3 ACCESS
- DESTROY SNMPv3 COMMUNITY
- DESTROY SNMPv3 GROUP
- DESTROY SNMPv3 NOTIFY
- DESTROY SNMPv3 TARGETADDR
- DESTROY SNMPv3 TARGETPARMS
- DESTROY SNMPV3 VIEW
- PURGE SNMPV3 ACCESS
- PURGE SNMPV3 COMMUNITY
- PURGE SNMPV3 NOTIFY
- PURGE SNMPV3 TARGETADDR
- PURGE SNMPV3 VIEW
- SET SNMPV3 ACCESS
- SET SNMPV3 COMMUNITY
- SET SNMPV3 GROUP
- SET SNMPV3 NOTIFY
- SET SNMPV3 TARGETADDR
- SET SNMPV3 TARGETPARAMS
- SET SNMPV3 USER
- SET SNMPV3 VIEW
- SHOW SNMPV3 ACCESS
- SHOW SNMPV3 COMMUNITY
- SHOW SNMPv3 GROUP
- SHOW SNMPV3 NOTIFY
- SHOW SNMPV3 TARGETADDR
- SHOW SNMPV3 TARGETPARAMS
- SHOW SNMPV3 USER
- SHOW SNMPV3 VIEW
- Section V
- Spanning Tree Protocols
- Chapter 26
- Spanning Tree Protocol Commands
- Chapter 27
- Rapid Spanning Tree Protocols Commands
- Chapter 28
- Multiple Spanning Tree Protocol Commands
- Section VI
- Virtual LANs
- Chapter 29
- Port-based, Tagged, and Multiple Mode VLAN Commands
- Chapter 30
- GARP VLAN Registration Protocol Commands
- Chapter 31
- Protected Ports VLAN Commands
- Chapter 32
- MAC Address-based VLAN Commands
- Section VII
- Port Security
- Chapter 33
- MAC Address-based Port Security Commands
- Chapter 34
- 802.1x Port-based Network Access Control Commands
- Section VIII
- Management Security
- Chapter 35
- Web Server Commands
- Chapter 36
- Encryption Key Commands
- Chapter 37
- Public Key Infrastructure (PKI) Certificate Commands
- Chapter 38
- Secure Sockets Layer (SSL) Commands
- Chapter 39
- Secure Shell (SSH) Commands
- Chapter 40
- TACACS+ and RADIUS Commands
- Chapter 41
- Management ACL Commands
- Index

AT-S63 Management Software Command Line Interface User’s Guide
Section II: Advanced Operations 361
SET DOS SYNFLOOD
Syntax
set dos synflood port=
port
state=enable|disable
Parameters
port Specifies the switch ports on which you want to enable
or disable this DoS defense. You can select more than
one port at a time.
state Specifies the state of the DoS defense. The options
are:
enable Activates the defense.
disable Deactivates the defense. This is the default.
Description
This command activates and deactivates the SYN ACK Flood DoS
defense.
In this type of attack, an attacker, seeking to overwhelm a victim with TCP
connection requests, sends a large number of TCP SYN packets with
bogus source addresses to the victim. The victim responds with SYN ACK
packets, but since the original source addresses are bogus, the victim
node does not receive any replies. If the attacker sends enough requests
in a short enough period, the victim may freeze operations once the
requests exceed the capacity of its connections queue.
To defend against this form of attack, a switch port monitors the number of
ingress TCP-SYN packets it receives. If a port receives more 60 TCP-SYN
packets per second, the following occurs.
The switch sends a trap to the management stations
The switch blocks all traffic on the port for one minute.
This defense mechanism does not involve the switch’s CPU. You can
activate it on as many ports as you want without it impacting switch
performance.
Example
The following command activates the defense on ports 18 to 20:
set dos synflood port=18-20 state=enable