This sample configuration demonstrates how to set up the PIX Firewall for access to a mail server located on the outside network. 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:
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.
In this section, you are presented with the information to configure the features described in this document.
Note: Use the Command Lookup Tool ( registered customers only) to obtain more information on the commands used in this section.
This document uses this network setup:
This document uses these configurations:
PIX Firewall |
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 209.64.3.1 255.255.255.252 ! 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 209.64.3.129 through 209.64.3.253 and contains a subnet !--- mask of 255.255.255.128.
global (outside) 1 209.64.3.129-209.64.3.253 netmask 255.255.255.128
!--- This command reserves the last available address (209.64.3.254) 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) 1 209.64.3.254
!--- 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 209.64.3.2.
route outside 0.0.0.0 0.0.0.0 209.64.3.2 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 |
Router A |
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 |
Router B |
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 209.64.3.2 255.255.255.252 no ip directed-broadcast ! interface Ethernet1
!--- Assigns an IP address to the server-facing Ethernet interface.
ip address 209.64.3.5 255.255.255.252 no ip directed-broadcast ! interface Serial0
!--- Assigns an IP address to the Internet-facing interface.
ip address 209.64.3.9 255.255.255.252 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 !--- 209.64.3.128 network (the PIX global pool) to the PIX to be translated !--- back to the inside addresses.
ip route 209.64.3.128 255.255.255.128 209.64.3.1 ! ! line con 0 transport input none line aux 0 autoselect during-login line vty 0 4 exec-timeout 5 0 password ww login ! end |
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.
The Output Interpreter Tool ( registered customers only) (OIT) supports certain show commands. Use the OIT to view an analysis of show command output.