在ESA上查找DHAP警报信息

简介

本文档介绍如何在思科邮件安全设备(ESA)上查找与目录搜集攻击防御(DHAP)警报相关的信息。

从ESA查找DHAP事件

描述DHAP事件的条目驻留在邮件日志中。以下是发生DHAP时的邮件日志条目示例：

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

注意：默认情况下，搜索中会查找/24网络掩码。

在CLI中输入以下查询以查看邮件日志：

myesa.local> grep "dhap_limit=" mail_logs

DHAP计数器包括收件人访问表(RAT)拒绝和轻型目录访问协议(LDAP)接受查询拒绝。DHAP设置在邮件流策略中配置。

从GUI查看或更新DHAP配置

要从GUI中查看或编辑您的DHAP配置参数，请完成以下步骤：

1. 导航到邮件策略>邮件流策略。
   
   
2. 单击策略名称进行编辑，或单击Default Policy Parameters查看当前DHAP配置。
   
   
3. 根据需要对目录搜集攻击预防(DHAP)部分进行更改：
   
   
   
   
4. 单击Submit，然后单击Commit以保存更改。

从CLI查看或更新DHAP配置

为了从CLI查看或编辑DHAP配置参数，请输入listenerconfig > edit [listener number] > hostaccess > default命令：

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]> 

如果选择进行更新，请确保返回主CLI提示符并提交所有更改。

相关信息

• 思科邮件安全设备-最终用户指南
• 技术支持和文档 - Cisco Systems