Тоже столкнулся с такой проблемой. Методом тыка нашёл решение. "clear authentication sessions all" - это не про то. Необходимо использовать "clear line".
Код:
Switch#show version
System MAC Address: 1C-5F-2B-2B-1B-40
Unit ID Module Name Versions
------- ------------------ ---------------------
1 DGS-1510-28 H/W:A1
Bootloader:1.00.012
Runtime:1.30.007
Код:
Switch#show users
ID Type User-Name Privilege Login-Time IP address
-------------------------------------------------------------------------------
0 console anonymous 1 22D18H46M54S
1 * telnet admin 15 11M2S 192.168.0.166
19 web admin 15 1H54M58S 192.168.0.166
20 web admin 15 1H45M59S 192.168.0.155
21 web admin 15 1H43M42S 192.168.0.166
22 web admin 15 1H33M24S 192.168.0.166
Total Entries: 6
Switch#clear line 19
Switch#clear line 20
Switch#clear line 21
Switch#clear line 22
Switch#show users
ID Type User-Name Privilege Login-Time IP address
-------------------------------------------------------------------------------
0 console anonymous 1 22D18H50M36S
1 * telnet admin 15 14M44S 192.168.0.166
Total Entries: 2