IronPort - Configuration Guide - AsyncOS 7.6.1

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Cisco IronPort AsyncOS 7.6 for Email Configuration Guide
Chapter 5 Configuring the Gateway to Receive Email
Mail delivery policies cannot be configured so that mail is delivered to multiple ports on a single IP
address (for example, port 25 for normal delivery and port 6025 for Cisco IronPort Spam quarantine).
Cisco recommends running each delivery option on a separate IP address or host. Further, it is not
possible to use the same hostname for regular email delivery and quarantine delivery.
Listeners support both Internet Protocol version 4 (IPv4) and version 6 (IPv6) addresses. You can use
either protocol version or both on a single listener. The listener uses the same protocol version for mail
delivery as the connecting host. For example, if the listener is configured for both IPv4 and IPv6 and
connects to a host that uses IPv6, the listener uses IPv6. However, if the listener is configured to only
use IPv6 addresses, it cannot connect to a host that is only using IPv4 addresses.
The System Setup Wizard or the systemsetup command (CLI) initially configures the IP interfaces that
run on the available Ethernet interfaces on the Cisco IronPort appliance. On Cisco IronPort C150 and
C160 appliances, these Ethernet interfaces are labeled Data1 and Data2. On all other Cisco IronPort
appliances, they are labeled Data1, Data2, and Management. You can edit these interfaces at a later time
via the IP Interfaces page on the Network menu or the interfaceconfig command. If you have
completed the GUI’s System Setup Wizard (or the systemsetup command) and committed the changes,
at least one listener should already be configured on the appliance. (Refer to the settings you entered in
the Step 3: Network, page 3-17.) The specific addresses to accept mail for were entered at that time, as
well as the first SMTP Routes (Network > SMTP Routes or smtproutes) entry.
Note When you create a new listener via the System Setup Wizard, AsyncOS creates the listener with default
values. However, when you create a listener manually, AsyncOS does not use these default SBRS values.
Use the Listeners page (Network > Listeners) or the listenerconfig command to configure listeners
that run over available IP interfaces on the Cisco IronPort appliance. For more information about
creating and configuring listeners, see the “Customizing Listeners” chapter in the Cisco IronPort
AsyncOS for Email Advanced Configuration Guide. In “Using Virtual Gateway Technology” in the
Cisco IronPort AsyncOS for Email Advanced Configuration Guide, the Cisco IronPort Virtual Gateway
technology is explained, in which you can further define and group IP interfaces over one or many IP
addresses, or groups of IP addresses.
Figure 5-1 Relationship Between Listeners, IP Interfaces, and Physical Ethernet Interfaces
Enterprise Gateway Configuration
Listener Port
IP interface
Physical Ethernet interface
IP address
Physical interface
IronPort Email
Security appliance
In this configuration, the Enterprise Gateway configuration accepts email from the Internet and relays
email to groupware servers, POP/IMAP servers, or other MTAs. At the same time, the enterprise gateway
accepts SMTP messages from groupware servers and other email servers for relay to recipients on the
Internet.
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