HP-UX Secure Shell Getting Started Guide

6 Enabling HP-UX Secure Shell to Take Advantage of High
Speed Networks
HP-UX Secure Shell includes a High Performance Enabled SSH/SCP (HPN) patch, which enables
HP-UX Secure Shell to take advantage of the large tcp send and receive buffers that are available
in high bandwidth networks.
In some situations (such as transfers on LANs), the HPN patch can degrade HP-UX Secure Shell
performance. In such cases, you can disable the HPN patch by setting HPNDisabled=no in the
sshd_config and ssh_config files. By default, the HPN patch is turned on.
Table 6-1 lists configuration directives that you can use to configure the HPN patch.
Table 6-1 Configuration Directives to Configure the HPN Patch
FunctionalityLocationConfiguration Directive
Use this configuration directive to set
the TCP socket receive buffer to n
Kilobytes. You can set the buffer up to
the maximum socket size allowed by
the system. Use this configuration
directive in situations when the tcp
receive window is set low, but the
maximum buffer size is set higher. The
default value of this directive is the
current systemwide tcp receive buffer
size.
Present on client
TcpRcvBuf=[int]KB
Use this configuration directive to
enable or disable the polling of the tcp
receive buffer while the connection is
active. The default value of this
directive is no.
Present on client and server
TcpRcvBufPoll=[yes/no]
Use this configuration directive to
enable or disable the use of the None
cipher. The default value of this
directive is no.
IMPORTANT: Enable this directive
with caution, because this allows users
to send unencrypted data through the
network. However, authentication
information remains encrypted.
Present on client and server
NoneEnabled=[yes/no]
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