In diesem Dokument wird beschrieben, wie Sie Informationen zu DHAP-Warnmeldungen (Directory Harvest Attack Prevention) auf Ihrer Cisco Email Security Appliance (ESA) finden.
Die Einträge, die das DHAP-Ereignis beschreiben, befinden sich in den Mail-Protokollen. Im Folgenden finden Sie ein Beispiel für einen Eintrag im Mailprotokoll, wenn DHAP auftritt:
Tue Oct 18 00:25:35 2005 Warning: LDAP: Dropping connection due to potential Directory
Harvest Attack from host=(192.168.10.1', None), dhap_limit=4, sender_group=SUSPECTLIST
Geben Sie diese Abfrage in die CLI ein, um die E-Mail-Protokolle anzuzeigen:
myesa.local> grep "dhap_limit=" mail_logs
Die DHAP-Zähler enthalten RAT-Ablehnungen (Recipient Access Table) und LDAP-Annahmeabfrageablehnungen (Lightweight Directory Access Protocol). Die DHAP-Einstellungen werden in der Mail Flow-Richtlinie konfiguriert.
Gehen Sie wie folgt vor, um die DHCP-Konfigurationsparameter über die GUI anzuzeigen oder zu bearbeiten:
Um Ihre DHAP-Konfigurationsparameter über die CLI anzuzeigen oder zu bearbeiten, geben Sie den Befehl listenerconfig > edit [listener number] > hostaccess > default ein:
Default Policy Parameters
==========================
Maximum Message Size: 10M
Maximum Number Of Concurrent Connections From A Single IP: 10
Maximum Number Of Messages Per Connection: 10
Maximum Number Of Recipients Per Message: 50
Directory Harvest Attack Prevention: Enabled
Maximum Number Of Invalid Recipients Per Hour: 25
Maximum Number Of Recipients Per Hour: Disabled
Maximum Number of Recipients per Envelope Sender: Disabled
Use SenderBase for Flow Control: Yes
Spam Detection Enabled: Yes
Virus Detection Enabled: Yes
Allow TLS Connections: No
Allow SMTP Authentication: No
Require TLS To Offer SMTP authentication: No
DKIM/DomainKeys Signing Enabled: No
DKIM Verification Enabled: No
SPF/SIDF Verification Enabled: No
DMARC Verification Enabled: No
Envelope Sender DNS Verification Enabled: No
Domain Exception Table Enabled: No
Accept untagged bounces: No
There are currently 5 policies defined.
There are currently 8 sender groups.
Choose the operation you want to perform:
- NEW - Create a new entry.
- EDIT - Modify an entry.
- DELETE - Remove an entry.
- MOVE - Move an entry.
- DEFAULT - Set the defaults.
- PRINT - Display the table.
- IMPORT - Import a table from a file.
- EXPORT - Export the table to a file.
- RESET - Remove senders and set policies to system default.
[]> default
Enter the default maximum message size. Add a trailing k for kilobytes, M for
megabytes, or no letter for bytes.
[10M]>
Enter the maximum number of concurrent connections allowed from a single IP address.
[10]>
Enter the maximum number of messages per connection.
[10]>
Enter the maximum number of recipients per message.
[50]>
Do you want to override the hostname in the SMTP banner? [N]>
Would you like to specify a custom SMTP acceptance response? [N]>
Would you like to specify a custom SMTP rejection response? [N]>
Do you want to enable rate limiting per host? [N]>
Do you want to enable rate limiting per envelope sender? [N]>
Do you want to enable Directory Harvest Attack Prevention per host? [Y]>
Enter the maximum number of invalid recipients per hour from a remote host.
[25]>
Select an action to apply when a recipient is rejected due to DHAP:
1. Drop
2. Code
[1]>
Would you like to specify a custom SMTP DHAP response? [Y]>
Enter the SMTP code to use in the response. 550 is the standard code.
[550]>
Enter your custom SMTP response. Press Enter on a blank line to finish.
Would you like to use SenderBase for flow control by default? [Y]>
Would you like to enable anti-spam scanning? [Y]>
Would you like to enable anti-virus scanning? [Y]>
Do you want to allow encrypted TLS connections?
1. No
2. Preferred
3. Required
4. Preferred - Verify
5. Required - Verify
[1]>
Would you like to enable DKIM/DomainKeys signing? [N]>
Would you like to enable DKIM verification? [N]>
Would you like to change SPF/SIDF settings? [N]>
Would you like to enable DMARC verification? [N]>
Would you like to enable envelope sender verification? [N]>
Would you like to enable use of the domain exception table? [N]>
Do you wish to accept untagged bounces? [N]>
Wenn Sie Aktualisierungen vornehmen möchten, stellen Sie sicher, dass Sie zur Haupt-CLI-Eingabeaufforderung zurückkehren und alle Änderungen bestätigen.
Überarbeitung | Veröffentlichungsdatum | Kommentare |
---|---|---|
1.0 |
23-Apr-2015 |
Erstveröffentlichung |