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Showing posts from August, 2014

MAC Authentication Bypass

One of the method to control your network is using MAB feature. It is helpful in case you have devices without dot1x functionality. Today I will try to implement basic configuration and analyze log messages. There is only one switch SW1 and one device attached to port Fa1/0/2.   ! aaa new - model aaa authentication dot1x default group radius ! ! int Fas1 / 0 / 2 authentication host - mode single - host authentication port - control auto mab ! I haven’t configured ACS yet but let’s see what error message I receive:   SW1 ( config - if ) # mab - ev ( Fa1 / 0 / 2 ): Received MAB context create from AuthMgr mab - ev ( Fa1 / 0 / 2 ): Created MAB client context 0x1100000F mab : initial state mab_initialize has enter mab - ev ( Fa1 / 0 / 2 ): Sending create new context event to EAP from MAB for 0x1100000F ( 0000.0000 . 0000 ) mab - sm ( Fa1 / 0 / 2 ): Received event 'MAB_START' on handle 0x1100000F mab : during state mab_initi...

ACS, tacacs+ and management access to router

I would like to test tacacs+ authentication on routers.   R1 #sh run aaa ! aaa authentication login ACS group tacacs + aaa authentication enable default group tacacs + ! ! ! ! ! ! tacacs - server host 192.168 . 157.100 key cisco aaa new - model aaa session - id common ! ! R1 # R1 #sh run | b line vty 0 4 line vty 0 4 login authentication ACS ! On ACS I added R1 as ND and ‘user1’ to the local database.   telnet 192.168 . 157.100 R1 # * Aug 27 15 : 37 : 05.071 : TPLUS : Queuing AAA Authentication request 49 for processing * Aug 27 15 : 37 : 05.075 : TPLUS : processing authentication start request id 49 * Aug 27 15 : 37 : 05.079 : TPLUS : Authentication start packet created for 49 () * Aug 27 15 : 37 : 05.079 : TPLUS : Using server 192.168 . 157.100 * Aug 27 15 : 37 : 05.087 : TPLUS ( 00000031 )/ 0 / NB_WAIT / 685E7C1C : Started 5 sec timeout * Aug 27 15 : 37 : 05.099 : TPLUS ( 00000031 )/ 0 / NB_WAIT : so...