Dell Force10 MXL Blade - Command Authorization; Protection from TCP Tiny and Overlapping Fragment Attacks

Security | 493
To delete a TACACS+ server host, use the no tacacs-server host {hostname | ip-address} command.
Command Authorization
The AAA command authorization feature configures FTOS to send each configuration command to a
TACACS server for authorization before it is added to the running configuration.
By default, the AAA authorization commands configure the system to check both the EXEC mode and
CONFIGURATION mode commands. To enable only EXEC mode command checking, use the
no aaa
authorization config-commands
command.
If rejected by the AAA server, the command is not added to the running config, and messages similar to
Message 1 are displayed.
Protection from TCP Tiny and Overlapping Fragment
Attacks
Tiny and overlapping fragment attack is a class of attack where configured ACL entries—denying TCP
port-specific traffic—can be bypassed, and traffic can be sent to its destination although denied by the
ACL. RFC 1858 and 3128 proposes a countermeasure to the problem. This countermeasure is configured
into the stack units and enabled by default.
Message 1 Configuration Command Rejection
04:07:48: %RPM0-P:CP %SEC-3-SEC_AUTHORIZATION_FAIL: Authorization failure Command
authorization failed for user (denyall) on vty0 ( 10.11.9.209 )
freebsd2# telnet 2200:2200:2200:2200:2200::2202
Trying 2200:2200:2200:2200:2200::2202...
Connected to 2200:2200:2200:2200:2200::2202.
Escape character is '^]'.
Login: admin
Password:
FTOS#
FTOS#