HP-UX Secure Shell Getting Started Guide HP-UX 11i v1, HP-UX 11i v2, and HP-UX 11i v3 (5900-3142, June 2013)

Table 18 Configuration Directives to Configure the HPN Patch (continued)
FunctionalityLocationConfiguration Directive
a local area network. By default
HPNDisabled is set to yes.
Use this configuration directive to set
the buffer size when interacting with
Present on client and serverHPNBufferSize=[int] KB
Secure Shell installations that do not
have the HPN patch. The value of this
directive ranges from 1 KB to 14 MB.
The default value of this directive is 2
MB. If TcpRecvBufPoll is set to yes,
this overrides the value specified in
HPNBufferSize.
CAUTION: Use of oversized or
undersized buffers can cause
performance issues depending on the
length of the network path.
NOTE: A client with the HPN patch can work with a non-HPN-enabled sshd server. However,
the client-server connection does not result in optimal performance. While establishing a connection,
the ssh client checks the server version. If the server version has a -hpn suffix, the client assumes
that the server is HPN-enabled, and dynamically adjusts the window size based on the tcp buffer
size. If the server version does not have a -hpn suffix, the client assumes that the server does not
have the HPN patch, and retains the window size to 128 KB.
Changes to the ssh command due to the HPN Patch
Due to the inclusion of the HPN patch, the-w option in the SSH command is replaced with the
TcpRecvBuf configuration directive.
54 Enabling HP-UX Secure Shell to Take Advantage of High Speed Networks