diff options
Diffstat (limited to 'lib/ssh/doc/src/ssh.xml')
| -rw-r--r-- | lib/ssh/doc/src/ssh.xml | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/lib/ssh/doc/src/ssh.xml b/lib/ssh/doc/src/ssh.xml index 7fbd70c87e..5a141ced3c 100644 --- a/lib/ssh/doc/src/ssh.xml +++ b/lib/ssh/doc/src/ssh.xml @@ -307,18 +307,31 @@ <tag><c><![CDATA[{negotiation_timeout, integer()}]]></c></tag> <item> - <p>Max time in milliseconds for the authentication negotiation. The default value is 2 minutes. + <p>Max time in milliseconds for the authentication negotiation. The default value is 2 minutes. If the client fails to login within this time, the connection is closed. + </p> + </item> + + <tag><c><![CDATA[{max_sessions, pos_integer()}]]></c></tag> + <item> + <p>The maximum number of simultaneous sessions that are accepted at any time for this daemon. This includes sessions that are being authorized. So if set to <c>N</c>, and <c>N</c> clients have connected but not started the login process, the <c>N+1</c> connection attempt will be aborted. If <c>N</c> connections are authenticated and still logged in, no more loggins will be accepted until one of the existing ones log out. + </p> + <p>The counter is per listening port, so if two daemons are started, one with <c>{max_sessions,N}</c> and the other with <c>{max_sessions,M}</c> there will be in total <c>N+M</c> connections accepted for the whole ssh application. + </p> + <p>Note that if <c>parallel_login</c> is <c>false</c>, only one client at a time may be in the authentication phase. + </p> + <p>As default, the option is not set. This means that the number is not limited. </p> </item> <tag><c><![CDATA[{parallel_login, boolean()}]]></c></tag> <item> - <p>If set to false (the default value), only one login is handled a time. If set to true, an unlimited logins will be allowed simultanously. Note that this affects only the connections with authentication in progress, not the already authenticated connections. + <p>If set to false (the default value), only one login is handled a time. If set to true, an unlimited number of login attempts will be allowed simultanously. + </p> + <p>If the <c>max_sessions</c> option is set to <c>N</c> and <c>parallel_login</c> is set to <c>true</c>, the max number of simultaneous login attempts at any time is limited to <c>N-K</c> where <c>K</c> is the number of authenticated connections present at this daemon. </p> <warning> - <p>Do not enable parallel_logins without protecting the server by other means like a firewall. If set to true, there is no protection against dos attacs.</p> + <p>Do not enable <c>parallel_logins</c> without protecting the server by other means, for example the <c>max_sessions</c> option or a firewall configuration. If set to <c>true</c>, there is no protection against DOS attacks.</p> </warning> - </item> <tag><c><![CDATA[{key_cb, atom()}]]></c></tag> |