HI,
(config-if)#authentication control-direction in
this command is used to change the port control to unidirectional(means in one direction) or or bidirectional(means in both direction).
http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/53SG/command/reference/cmdref/ch2a_ins.html#wp1712844
(config-if)#authentication open
it enables access to a port so as to allow clients or devices to gain network access before authentication
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/security/a1/sec-a1-xe-3se-3850-cr-book/sec-a1-xe-3se-3850-cr-book_chapter_010.html
(config-if)#authentication periodic
it enables or disables reauthentication on a port
(config-if)#authentication timer reauthentication
helps to configure the amount of timebetween periodic re-authentication attempts
http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750/software/release/12-2_52_se/command/reference/3750cr/cli1.html#wpmkr11888284
(config-if)#authentication port-control auto
this command causes the port to begin in a unauthorised state
http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/53SG/command/reference/cmdref/ch2a_ins.html
(config-if)#authentication host-mode multi-domain
Allows one client on the voice vlan and multiple authenticated clients on the data vlans
http://www.cisco.com/en/US/docs/ios-xml/ios/sec_usr_8021x/configuration/15-2mt/sec-ieee-mda.html
(config-if)#authentication event server alive action reinitialize
it reinitialize an authorized session when a previously unreachable AAA server becomes available
(config-if)#authentication event server dead action authorize
to authorize auth manager sessions when AAA server becomes unreachable
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/security/a1/sec-a1-xe-3se-3850-cr-book/sec-a1-xe-3se-3850-cr-book_chapter_010.html
(config-if)#authentication violation restrict
helps to change the port to restricted mode when a new device connects by generating a system error message.
http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-0_2_EX/security/command_reference/b_sec_152ex_2960-x_cr/b_sec_152ex_2960-x_cr_chapter_010.html
Regards
Aateek singh
Network Engineer
Spooster IT Services
