On Thu, 8 Oct 2015 11:18:17 +0800 Hua Wang wrote: > I tried to ping the server, and it can accept all data. Is there a good way > to check it? ssh -v, ssh -vv and ssh -vvv might give you some interesting information. > The problem came out while reinstalling centos 7.7. Since you're apparently using some kind of an unofficial or non-standard version of Centos, you might want to try using a current (regular) one instead. -- MELVILLE THEATRE ~ Real D 3D Digital Cinema ~ www.melvilletheatre.com