이 문서에서는 Cisco ESA(Email Security Appliance)의 블랙리스트에 악성 IP 주소 또는 도메인 이름을 추가하는 방법에 대해 설명합니다.
발신자를 블랙리스트에 추가하는 가장 쉬운 방법은 ESA HAT(Host Access Table) 내의 BLACKLIST 발신자 그룹에 IP 주소 또는 도메인 이름을 추가하는 것입니다. BLACKLIST 발신자 그룹은 액세스 규칙이 REJECT인 $BLOCKED 메일 플로우 정책을 사용합니다.
GUI를 통해 발신자를 블랙리스트에 추가하려면 다음 단계를 완료합니다.
다음은 CLI를 통해 도메인 이름 및 IP 주소로 발신자를 블랙리스트에 추가하는 방법을 보여 주는 예입니다.
myesa.local> listenerconfig
Currently configured listeners:
1. Bidirectional (on Management, 172.18.249.222) SMTP TCP Port 25 Public
Choose the operation you want to perform:
- NEW - Create a new listener.
- EDIT - Modify a listener.
- DELETE - Remove a listener.
- SETUP - Change global settings.
[]> edit
Enter the name or number of the listener you wish to edit.
[]> 1
Name: Bidirectional
Type: Public
Interface: Management (172.18.249.222/24) TCP Port 25
Protocol: SMTP
Default Domain: example.com
Max Concurrent Connections: 50 (TCP Queue: 50)
Domain Map: Disabled
TLS: No
SMTP Authentication: Disabled
Bounce Profile: Default
Use SenderBase For Reputation Filters and IP Profiling: Yes
Footer: None
Heading: None
SMTP Call-Ahead: Disabled
LDAP: Off
Choose the operation you want to perform:
- NAME - Change the name of the listener.
- INTERFACE - Change the interface.
- CERTIFICATE - Choose the certificate.
- LIMITS - Change the injection limits.
- SETUP - Configure general options.
- HOSTACCESS - Modify the Host Access Table.
- RCPTACCESS - Modify the Recipient Access Table.
- BOUNCECONFIG - Choose the bounce profile to use for messages injected on this
listener.
- MASQUERADE - Configure the Domain Masquerading Table.
- DOMAINMAP - Configure domain mappings.
- LDAPACCEPT - Configure an LDAP query to determine whether a recipient address
should be accepted or bounced/dropped.
- LDAPGROUP - Configure an LDAP query to determine whether a sender or recipient
is in a specified group.
[]> hostaccess
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
Allow TLS Connections: No
Allow SMTP Authentication: No
Require TLS To Offer SMTP authentication: No
DKIM/DomainKeys Signing Enabled: No
DKIM Verification Enabled: No
S/MIME Public Key Harvesting Enabled: Yes
S/MIME Decryption/Verification Enabled: Yes
SPF/SIDF Verification Enabled: Yes
Conformance Level: SIDF compatible
Downgrade PRA verification: No
Do HELO test: Yes
SMTP actions:
For HELO Identity: Accept
For MAIL FROM Identity: Accept
For PRA Identity: Accept
Verification timeout: 40
DMARC Verification Enabled: No
Envelope Sender DNS Verification Enabled: No
Domain Exception Table Enabled: Yes
There are currently 6 policies defined.
There are currently 7 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.
[]> edit
1. Edit Sender Group
2. Edit Policy
[1]> 1
Currently configured HAT sender groups:
1. ALLOWSPOOF
2. MY_INBOUND_RELAY
3. WHITELIST (My trusted senders have no anti-spam scanning or rate limiting)
4. BLACKLIST (Spammers are rejected)
5. SUSPECTLIST (Suspicious senders are throttled)
6. UNKNOWNLIST (Reviewed but undecided, continue normal acceptance)
7. (no name, first host = ALL) (Everyone else)
Enter the sender group number or name you wish to edit.
[]> 4
Choose the operation you want to perform:
- NEW - Add a new host.
- DELETE - Remove a host.
- POLICY - Change the policy settings and options.
- PRINT - Display the current definition.
- RENAME - Rename this sender group.
[]> new
Enter the senders to add to this sender group. A sender group entry can be
any of the following:
- an IP address
- a CIDR address such as 10.1.1.0/24 or 2001::0/64
- an IP range such as 10.1.1.10-20, 10.1.1-5 or 2001:db8::1-2001:db8::10.
- an IP subnet such as 10.2.3.
- a hostname such as crm.example.com
- a partial hostname such as .example.com
- a range of SenderBase Reputation Scores in the form SBRS[7.5:10.0]
- a SenderBase Network Owner ID in the form SBO:12345
- a remote blacklist query in the form dnslist[query.blacklist.example]
Separate multiple entries with commas.
[]> badhost.example.org, 10.1.1.10