Zoek de DHAP-waarschuwingsinformatie op de ESA

Inleiding

Dit document beschrijft hoe u informatie kunt vinden met betrekking tot DHAP-waarschuwingen (Directory Harvest Attack Prevention) voor uw Cisco e-mail security applicatie (ESA).

Zoek DHAP-incidenten vanuit de ESA

De vermeldingen die de DHAP-gebeurtenis beschrijven, bevinden zich in de e-maillogbestanden. Hier volgt een voorbeeld van een e-maillogbestand wanneer DHAP optreedt:

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

Opmerking: standaard wordt het /24 netmasker gezocht in de zoekactie.

Voer deze zoekopdracht in de CLI in om de e-maillogbestanden te bekijken:

myesa.local> grep "dhap_limit=" mail_logs

De DHAP-tellers omvatten zowel RAT-afwijzingen (RAT) van de RAT (Recipient Access Table) als LDAP-afwijzingen van acceptatievragen. De DHAP-instellingen worden ingesteld in het Mail Flow-beleid.

DHAP-configuratie vanuit de GUI bekijken of bijwerken

Voltooi deze stappen om uw DHAP-configuratieparameters te bekijken of bewerken vanuit de GUI:

1. Ga naar Mail Beleid > Mail Flow Beleid.
   
   
2. Klik op de beleidsnaam om bewerkingen uit te voeren of klik op Default Policy Parameters om de huidige DHAP-configuratie te bekijken.
   
   
3. Breng indien nodig wijzigingen aan in de sectie Directory Harvest Attack Prevention (DHAP):
   
   
   
   
4. Klik op Indienen en klik vervolgens op Toewijzen om uw wijzigingen op te slaan.

DHAP-configuratie vanuit de CLI bekijken of bijwerken

Om uw DHAP configuratieparameters van de CLI te bekijken of te bewerken, voert u listenerconfig > edit [lister number] > hostaccess > default commando in:

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]> 

Als u ervoor kiest om updates te maken, zorg er dan voor dat u terugkeert naar de belangrijkste CLI-prompt en alle wijzigingen doorvoert.

Gerelateerde informatie

• Cisco e-mail security applicatie - eindgebruikershandleidingen
• Technische ondersteuning en documentatie - Cisco Systems