Continuous AAA.authfail in Logs !!! Need help

[Prashanth_Kumar]

I Am having a continuous logs in my switch . see some logs below for reference

04/05/2017 09:00:55.66 Login failed for user shell through telnet (5.140.0.7)04/05/2017 09:00:55.34 Login failed for user enable through telnet (70.91.21.21)
04/05/2017 09:00:54.12 Login failed for user enable through telnet (5.140.0.7)
04/05/2017 09:00:53.66 Login failed for user supervisor through telnet (70.91.21.21)
04/05/2017 09:00:53.39 Login failed for user root through telnet (5.140.0.7)
04/05/2017 09:00:52.30 Switch, Code 5: Air flow mismatch detected in slot 1. Ensure all fantray and psu models are of similar air flow. (X460G2-48t-10G4, P/N: 800550-00-04, S/N: 1503N-40087, Rev: 4.0)
[7mPress to continue or to quit: [m [60;D [K04/05/2017 09:00:51.68 Login failed for user shell through telnet (70.91.21.21)
04/05/2017 09:00:51.50 Login failed for user shell through telnet (5.140.0.7)
04/05/2017 09:00:50.06 Login failed for user enable through telnet (70.91.21.21)
04/05/2017 09:00:49.61 Login failed for user enable through telnet (5.140.0.7)
04/05/2017 09:00:48.45 Login failed for user admin through telnet (70.91.21.21)
04/05/2017 09:00:47.99 Login failed for user root through telnet (5.140.0.7)
04/05/2017 09:00:46.75 Login failed for user shell through telnet (70.91.21.21)
04/05/2017 09:00:46.16 Login failed for user shell through telnet (5.140.0.7)
04/05/2017 09:00:45.07 Login failed for user enable through telnet (70.91.21.21)
04/05/2017 09:00:44.47 Login failed for user enable through telnet (5.140.0.7)
04/05/2017 09:00:43.90 Login failed for user enable through telnet (78.188.179.98)
04/05/2017 09:00:43.42 Login failed for user admin through telnet (70.91.21.21)
04/05/2017 09:00:42.90 Login failed for user root through telnet (5.140.0.7)
04/05/2017 09:00:41.39 Login failed for user shell through telnet (70.91.21.21)

This is continuously repeating in the logs ... is there a way to resolve this

[Steven_Lin]

Hello Prashanth,
Below article will guide you to restrict the telnet access
https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-restrict-telnet-access

[Nick_Yakimenko]

you should make an access list with a list of allowed ip-adresses to have access through telnet
OR if you do not manage your switch through telnet -- just disable that