Hallo, auf meinem Ubuntu Server 16.04 läuft Dovecot im Rahmen eines Mailservers und der "saslauthd" schreibt unzählige Loginversuchte in die auth.log Datei. Ich vermute das dieses meinen Server zeitweise in die Knie zwingt. Kann ich das irgendwie sperren das er die nicht mehr an nimmt oder ggf. nur bestimmte Benutzer zulassen?
Hier ein kurzer Log-Auszug:
Jun 30 21:39:42 server14045 saslauthd[1293]: do_auth : auth failure: [user=inge] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:40:19 server14045 saslauthd[1295]: do_auth : auth failure: [user=corinna] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:40:56 server14045 saslauthd[1294]: do_auth : auth failure: [user=china] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:41:32 server14045 saslauthd[1291]: do_auth : auth failure: [user=jelibean] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:42:04 server14045 saslauthd[1290]: do_auth : auth failure: [user=pixel] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:42:46 server14045 saslauthd[1293]: do_auth : auth failure: [user=dinko] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:43:23 server14045 saslauthd[1295]: do_auth : auth failure: [user=lueg] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:43:54 server14045 saslauthd[1294]: do_auth : auth failure: [user=fotograf] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:44:36 server14045 saslauthd[1293]: do_auth : auth failure: [user=beavis] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:45:14 server14045 saslauthd[1290]: do_auth : auth failure: [user=paul2] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:45:24 server14045 saslauthd[1295]: do_auth : auth failure: [user=scan] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:45:50 server14045 saslauthd[1291]: do_auth : auth failure: [user=bake5] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:46:27 server14045 saslauthd[1294]: do_auth : auth failure: [user=dbmaker] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username] Jun 30 21:47:03 server14045 saslauthd[1290]: do_auth : auth failure: [user=mgonzalez] [service=smtp] [realm=nitschke-marl.de] [mech=shadow] [reason=Invalid username]