Addendum

Example
FTOS(conf)#ipv6 icmp source-interface tengigabitethernet 0/0
FTOS(conf)#
Configuring the Duration to Establish a TCP Connection
This procedure is supported on the S4810, S4820T, S6000, Z9000, I/O Aggregator, and MXL platforms.
You can configure the amount of time for which the device must wait before it attempts to establish a
TCP connection. Using this capability, you can limit the wait times for TCP connection requests. Upon
responding to the initial SYN packet that requests a connection to the router for a specific service (such
as SSH or BGP) with a SYN ACK, the router waits for a period of time for the ACK packet to be sent from
the requesting host that will establish the TCP connection.
You can set this duration or interval for which the TCP connection waits to be established to a
significantly high value to prevent the device from an out-of-service condition or becoming unresponsive
during a SYN flood attack that occurs on the device. You can set the wait time to be 10 seconds or lower.
If the device does not contain any BGP connections with BGP neighbors across WAN links, you must set
this interval to a higher, appropriate value, depending on the complexity of your network and the
configuration attributes.
To configure the duration for which the device waits for the ACK packet to be sent from the requesting
host to establish the TCP connection, perform the following steps:
1. Define the wait duration in seconds for the TCP connection to be established.
CONFIGURATION mode
Dell(conf)#ip tcp reduced-syn-ack-wait <9-75>
You can use the no ip tcp reduced-syn-ack-wait command to restore the default behavior,
which causes the wait period to be set as 8 seconds.
2. View the interval that you configured for the device to wait before the TCP connection is attempted
to be established.
EXEC mode
Dell>show ip tcp reduced-syn-ack-wait
ip tcp initial-time
Define the wait duration in seconds for the TCP connection to be established. This command is
supported on the S4810, S4820T, S6000, Z9000, I/O Aggregator, and MXL platforms.
Syntax
ip tcp initial-time <8-75>
To restore the default behavior, which causes the wait period to be set as 8
seconds, use the no ip tcp initial-time command
Parameters
<8-75> Wait duration in seconds for the TCP connection to be
established.
Command
Modes
CONFIGURATION
Command
History
Version 9.3.0.0 Introduced on the S4810, S4820T, S6000, Z9000, I/O
Aggregator, and MXL platforms.
154
IPv4 Routing