Specify the port number that the server listens on (allowed
values are 1 - 65535). The server has to be restarted in order
to use the changed setting. The default port is 22.
- Listen address
Specify the IP address of the network interface card where the
Secure Shell server socket is bound. The server has to be
restarted in order to use the changed setting.
- Require reverse DNS mapping
This option is used to check whether the hostname DNS lookup must
succeed when checking if connections from hosts are allowed
using the Allow login from hosts and Deny login
from hosts options. For more information on these two
options, see Section Host Restrictions.
The possible options are the following:
- Yes: Reverse DNS mapping is required.
- No: Reverse DNS mapping is not required.
- No, but try: Reverse DNS mapping is not required, but the system attempts to use it. This is the default value.
If reverse DNS mapping is used and the name lookup fails, the
connection is denied. When this option is not used and the name
lookup fails, the remote host's IP address is used to check
whether it is allowed to connect. This is probably not what you
want if you have specified only hostnames (not IP addresses)
with the Allow/Deny login from hosts settings.
- TCP no delay
Specify this option to enable the socket option
. By default, this option is on.
- TCP keep alive
Specify whether the system should send
messages to the other side. If they are sent, loss of
connection or crash of one of the machines will be properly
noticed. However, this means that connections will die if the
route is down temporarily, which in some situations can be
annoying. On the other hand, if
keepalive messages are
not sent, sessions may hang indefinitely on the server, leaving
"ghost" users and consuming server resources.
The default value is to send
keepalive messages, which
means that the server will notice if the network fails or the
client host reboots. This helps to avoid infinitely hanging sessions.
keepalive messages, the option should be
disabled in both the server and the client configuration.