What kind of keepalive settings does the Tectia client and server have and how can I enable those?
asked Jan 10 '11 at 13:16
SSH KB ♦
SSH Tectia Client/Server can be configured to utilize two different keepalive features that serve different purposes. The client side can enable application level keepalives to make the connection look active. The server side can enable TCP keepalives to detect broken connections.
Application level keepalives
Application level keepalive means that the client will send no-op packets to server at certain intervals. The interval is configurable in the Tectia Connection Broker configuration. Typical use case is an environment where a network device closes idle connections and the user wants to prevent this for some connections.
The command line option for enabling the application level keepalives is following:
--keep-alive=VALUE Defines how often keep-alive messages are sent to the Secure Shell server. Enter the value as seconds. The default value is 0, meaning that keep-alive messages are disabled.
There is also a configuration option in ssh-broker-config.xml for enabling the keepalives, this option can be used in the default-settings and in connection profiles:
keepalive-interval This element specifies an interval for sending keepalive messages to the Secure Shell server. The time value is given in seconds. The default setting is 0, meaning that the keepalive messages are disabled. <keepalive-interval time="0" />
TCP keepalives can be enabled in the Tectia server configuration (ssh-server-config.xml) using the tcp-keepalive attribute in a <connection> element.
The tcp-keepalive attribute defines whether the system should send keepalive messages to the other side. If they are sent, a broken 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, and this can be annoying in some situations. 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 value must be yes or no. The default is no (do not send keepalives).
The interval for TCP keepalives is is a system-wide TCP setting and not configurable in the Tectia configuration. Typical value is 2 hours.
answered Jan 10 '11 at 13:17
SSH KB ♦