Enabling Nagle's Algorithm; Enabling Random Tcp Sequence Numbers - Cisco 4700M Configuration Manual

Chapter 4 Configuring TCP/IP Normalization and IP Reassembly Parameters

Enabling Nagle's Algorithm

Enabling Random TCP Sequence Numbers

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Configuring a Connection Parameter Map for TCP/IP Normalization and Termination
Nagle's algorithm instructs a sender to buffer any data to be sent until all
outstanding data has been acknowledged or until there is a full segment of data to
send. The algorithm automatically concatenates a number of small buffer
messages transmitted over the TCP connection. This process increases the
throughput by decreasing the number of segments that need to be sent over the
network. However, the interaction between the Nagle algorithm and the TCP
delay acknowledgment may increase latency in your TCP connection. You should
disable the Nagle algorithm when you observe an unacceptable delay in a TCP
connection.
You can enable Nagle's algorithm by using the nagle command in parameter map
connection configuration mode. By default, this command is disabled. The syntax
of this command is as follows:
nagle
For example, enter:
host1/C1(config-parammap-conn)# nagle
To disable Nagle's algorithm, enter:
host1/C1(config-parammap-conn)# no nagle
Randomizing TCP sequence numbers adds a measure of security to TCP
connections by making it more difficult for a hacker to guess or predict the next
sequence number in a TCP connection. This feature is enabled by default. To
enable TCP sequence number randomization after it has been disabled, use the
random-sequence-number command in parameter map connection
configuration mode.
The syntax of this command is as follows:
random-sequence-number
For example, to enable the use of random sequence numbers if you have disabled
the feature, enter:
host1/C1(config-parammap-conn)# random-sequence-number
Cisco 4700 Series Application Control Engine Appliance Security Configuration Guide
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