You can use below query, it picks all the connections from a host (ABC in this case) from sys.sysprocesses; creates a common statement to kill them; and then executes the statement.

Replace 'ABC' with hostname;

you can see which sessions it has killed by deleting the comment from 'print' section of the script

declare @SqlCmd varchar(1000), @HostName varchar(100)

-- Set the hostname name from which to kill the connections

set @HostName = 'ABC'

set @SqlCmd = ''

select @Sqlcmd = @SqlCmd + 'kill ' + convert(char(10), spid) + ' '

from master.dbo.sysprocesses

where hostname= @HostName

and

DBID <> 0

and

spid <> @@spid

exec (@Sqlcmd)

--print @sqlcmd

GO