This sample configuration demonstrates how to set up the PIX Firewall for access to a mail server located on the DMZ network.
Note: The SMTP inspection configured in this document is not compatible with ESMTP connections to servers such as Microsoft Exchange. Do not configure SMTP inspection if you use a mail server that relies on ESMTP. Alternatively, PIX Software version 7.0 and later supports SMTP and ESMTP inspection.
There are no specific prerequisites for this document.
The information in this document is based on these software and hardware versions:
PIX Firewall 515
PIX Firewall software release 6.3(3)
Cisco 3640 Router
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.
This document uses this network setup.
This document uses this configuration.
PIX Version 6.3(3) interface ethernet0 10baset interface ethernet1 10baset interface ethernet2 100full nameif ethernet0 outside security0 nameif ethernet1 inside security100 nameif ethernet2 dmz security10 enable password 2KFQnbNIdI.2KYOU encrypted passwd 2KFQnbNIdI.2KYOU encrypted hostname pixfirewall fixup protocol dns maximum-length 512 fixup protocol ftp 21 fixup protocol h323 h225 1720 fixup protocol h323 ras 1718-1719 fixup protocol http 80 fixup protocol rsh 514 fixup protocol rtsp 554 fixup protocol sip 5060 fixup protocol sip udp 5060 fixup protocol skinny 2000 fixup protocol smtp 25 fixup protocol sqlnet 1521 fixup protocol tftp 69 names !--- This access list allows hosts to access !--- IP address 22.214.171.124 for the SMTP port. access-list outside_int permit tcp any host 126.96.36.199 eq smtp !--- This access list allows host IP 172.16.31.10 !--- sourcing the SMTP port to access any host. access-list dmz_int permit tcp host 172.16.31.10 eq smtp any pager lines 24 logging on logging buffered debugging logging trap debugging logging host inside 10.1.1.55 mtu outside 1500 mtu inside 1500 mtu dmz 1500 ip address outside 188.8.131.52 255.255.255.224 ip address inside 10.1.1.1 255.255.255.0 ip address dmz 172.16.31.1 255.255.255.0 ip audit info action alarm ip audit attack action alarm no failover failover timeout 0:00:00 failover poll 15 no failover ip address outside no failover ip address inside no failover ip address dmz pdm history enable arp timeout 14400 global (outside) 1 184.108.40.206-220.127.116.11 netmask 255.255.255.224 global (outside) 1 18.104.22.168 nat (inside) 1 10.1.1.0 255.255.255.0 0 0 !--- This network static does not use address translation. !--- Inside hosts appear on the DMZ with their own addresses. static (inside,dmz) 10.1.1.0 10.1.1.0 netmask 255.255.255.0 0 0 !--- This network static uses address translation. !--- Hosts accessing the mail server from the outside !--- use the 22.214.171.124 address. static (dmz,outside) 126.96.36.199 172.16.31.10 netmask 255.255.255.255 0 0 access-group outside_int in interface outside access-group dmz_int in interface dmz route outside 0.0.0.0 0.0.0.0 188.8.131.52 1 timeout xlate 3:00:00 timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h225 1:00:00 timeout h323 0:05:00 mgcp 0:05:00 sip 0:30:00 sip_media 0:02:00 timeout uauth 0:05:00 absolute aaa-server TACACS+ protocol tacacs+ aaa-server RADIUS protocol radius aaa-server LOCAL protocol local no snmp-server location no snmp-server contact snmp-server community public no snmp-server enable traps floodguard enable crypto map mymap 30 ipsec-isakmp ! Incomplete telnet timeout 5 ssh timeout 5 console timeout 0 terminal width 80 Cryptochecksum:8c1aa55b41d6855f6745e04ce6eea614 : end [OK]
There is currently no verification procedure available for this configuration.
This section provides information you can use to troubleshoot your configuration.
Note: Refer to Important Information on Debug Commands before you use debug commands.
debug icmp trace—Shows whether Internet Control Message Protocol (ICMP) requests from the hosts reach the PIX. In order to run this debug, you need to add the access-list command to permit ICMP in your configuration.
logging buffer debugging—Shows connections that are established and denied to hosts that go through the PIX. The information is stored in the PIX log buffer, and the output can be seen with the show log command.
Refer to Setting Up the PIX Syslog for more information on how to set up logging.
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Refer to Cisco Technical Tips Conventions for information on conventions used in this document.