This sample configuration demonstrates how to set up the PIX Firewall for access to a mail server located on the outside network.
Refer to PIX/ASA 7.x and above : Mail Server Access on Inside Network Configuration Example in order to set up the PIX/ASA Security Appliance for access to a mail/SMTP server located on the Inside network.
Refer to PIX/ASA 7.x with Mail Server Access on DMZ Network Configuration Example in order to set up the PIX/ASA Security Appliance for access to a mail/SMTP server located on the DMZ network.
Refer to ASA 8.3 and Later: Mail (SMTP) Server Access on Outside Network Configuration Example for more information on the identical configuration on Cisco Adaptive Security Appliance (ASA) with version 8.3 and later.
Refer to the Cisco Secure PIX Firewall documentation for further information about how to set Microsoft Exchange. Choose your software version, then go to the configuration guide and read the chapter on how to configure for Microsoft Exchange.
There are no specific requirements for this document.
The information in this document is based on these software and hardware versions:
PIX Firewall 535
PIX Firewall software release 7.1(1)
Cisco 2500 Routers
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Refer to the Cisco Technical Tips Conventions for more information on document conventions.
This configuration can also be used with an Adaptive Security Appliance (ASA) that runs version 7.x and later.
In this section, you are presented with the information to configure the features described in this document.
This document uses this network setup:
This document uses these configurations:
PIX Version 7.1(1) ! hostname pixfirewall enable password 8Ry2YjIyt7RRXU24 encrypted names ! interface Ethernet0 shutdown no nameif no security-level no ip address ! interface Ethernet1 shutdown no nameif no security-level no ip address ! interface Ethernet2 shutdown no nameif no security-level no ip address ! !--- Define the IP address for the inside interface. interface Ethernet3 nameif inside security-level 100 ip address 192.168.1.1 255.255.255.252 ! !--- Define the IP address for the outside interface. interface Ethernet4 nameif outside security-level 0 ip address 220.127.116.11 255.255.255.252 ! interface Ethernet5 shutdown no nameif no security-level no ip address ! passwd 2KFQnbNIdI.2KYOU encrypted ftp mode passive pager lines 24 mtu inside 1500 mtu outside 1500 no failover no asdm history enable arp timeout 14400 !--- This command defines the global for the Network Address Translation !--- (NAT) statement. In this case, the two commands state that any traffic !--- from the 192.168.2.x network that passes from the inside interface (Ethernet0) !--- to the outside interface (Ethernet 1) translates into an address !--- in the range of 18.104.22.168 through 22.214.171.124 and contains a subnet !--- mask of 255.255.255.128. global (outside) 1 126.96.36.199-188.8.131.52 netmask 255.255.255.128 !--- This command reserves the last available address (184.108.40.206) for !--- for Port Address Translation (PAT). In the previous statement, !--- each address inside that requests a connection uses one !--- of the addresses specified. If all of these addresses are in use, !--- this statement provides a failsafe to allow additional inside stations !--- to establish connections. global (outside) 1 220.127.116.11 !--- This command indicates that all addresses in the 192.168.2.x range !--- that pass from the inside (Ethernet0) to a corresponding global !--- designation are done with NAT. !--- As outbound traffic is permitted by default on the PIX, no !--- static commands are needed. nat (inside) 1 192.168.2.0 255.255.255.0 !--- Creates a static route for the 192.168.2.x network with 192.168.1.2. !--- The PIX forwards packets with these addresses to the router !--- at 192.168.1.2. route inside 192.168.2.0 255.255.255.0 192.168.1.2 1 !--- Sets the default route for the PIX Firewall at 18.104.22.168. route outside 0.0.0.0 0.0.0.0 22.214.171.124 1 timeout xlate 3:00:00 timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02 timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 timeout mgcp-pat 0:05:00 sip 0:30:00 sip_media 0:02:00 timeout uauth 0:05:00 absolute no snmp-server location no snmp-server contact snmp-server enable traps snmp authentication linkup linkdown coldstart telnet timeout 5 ssh timeout 5 console timeout 0 ! class-map inspection_default match default-inspection-traffic ! ! !--- SMTP/ESMTP is inspected since "inspect esmtp" is included in the map. policy-map global_policy class inspection_default inspect dns maximum-length 512 inspect ftp inspect h323 h225 inspect h323 ras inspect rsh inspect rtsp inspect esmtp inspect sqlnet inspect skinny inspect sunrpc inspect xdmcp inspect sip inspect netbios inspect tftp ! service-policy global_policy global Cryptochecksum:8a63de5ae2643c541a397c2de7901041 : end
Current configuration: ! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname 2522-R4 ! enable secret 5 $1$N0F3$XE2aJhJlCbLWYloDwNvcV. ! ip subnet-zero ! ! ! ! ! interface Ethernet0 !--- Assigns an IP address to the inside Ethernet interface. ip address 192.168.2.1 255.255.255.0 no ip directed-broadcast ! interface Ethernet1 !--- Assigns an IP address to the PIX-facing interface. ip address 192.168.1.2 255.255.255.252 no ip directed-broadcast ! interface Serial0 no ip address no ip directed-broadcast shutdown ! interface Serial1 no ip address no ip directed-broadcast shutdown ! ip classless !--- This route instructs the inside router to forward all !--- non-local packets to the PIX. ip route 0.0.0.0 0.0.0.0 192.168.1.1 ! ! line con 0 transport input none line aux 0 autoselect during-login line vty 0 4 exec-timeout 5 0 password ww login ! end
Current configuration: ! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname 2522-R4 ! enable secret 5 $1$N0F3$XE2aJhJlCbLWYloDwNvcV. ! ip subnet-zero ! ! ! ! interface Ethernet0 !--- Assigns an IP address to the PIX-facing Ethernet interface. ip address 126.96.36.199 255.255.255.252 no ip directed-broadcast ! interface Ethernet1 !--- Assigns an IP address to the server-facing Ethernet interface. ip address 188.8.131.52 255.255.255.252 no ip directed-broadcast ! interface Serial0 !--- Assigns an IP address to the Internet-facing interface. ip address 184.108.40.206 255.255.255.252 no ip directed-broadcast no ip mroute-cache ! interface Serial1 no ip address no ip directed-broadcast ! ip classless !--- All non-local packets are to be sent out serial 0. In this case, !--- the IP address on the other end of the serial interface is not known, !--- or you can specify it here. ip route 0.0.0.0 0.0.0.0 serial 0 ! !--- This statement is required to direct traffic destined to the !--- 220.127.116.11 network (the PIX global pool) to the PIX to be translated !--- back to the inside addresses. ip route 18.104.22.168 255.255.255.128 22.214.171.124 ! ! line con 0 transport input none line aux 0 autoselect during-login line vty 0 4 exec-timeout 5 0 password ww login ! end
Note: If you use Transport Layer Security (TLS) encryption for e-mail communication then the ESMTP inspection feature (enabled by default) in the PIX drops the packets. In order to allow the e-mails with TLS enabled, disable the ESMTP inspection feature as this output shows.
pix(config)#policy-map global_policy pix(config-pmap)#class inspection_default pix(config-pmap-c)#no inspect esmtp pix(config-pmap-c)#exit pix(config-pmap)#exit
There is currently no verification procedure available for this configuration.
Note: Refer to Important Information on Debug Commands before you use debug commands.
The logging console debugging command directs messages to the PIX console. If connectivity to the mail server is a problem, examine the console debug messages to locate the IP addresses of the sending and receiving stations in order to determine the problem.
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Refer to Cisco Technical Tips Conventions for information on conventions used in this document.