Setup Cisco Pix506 for IMAP4 and SMTP (Ports 143,25, and 993)

Posted on 2007-11-21
Last Modified: 2010-04-21

I have a Cisco Pix506 that i need to setup to open ports and allow access for IMAP4, SMTP, and SSL IMAP4.  I know the ports are 143, 25, and 993 respectively  I am in the Cisco router, but am not sure of what the configuration lines to add to open these ports and allow access.

Here is what is in the config thus far, which leads me to believe I have SMTP (port 25) covered, I just need help adding the rest.

fixup protocol dns maximum-length 640                                    
fixup protocol ftp 21                    
fixup protocol h323 h225 1720                            
fixup protocol h323 ras 1718-1719                                
fixup protocol http 80                      
fixup protocol ils 389                      
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                      
access-list 101 permit tcp any any eq smtp                                          
access-list 101 permit tcp any any eq 3389                                          
access-list 101 permit tcp any any eq www                                        
access-list 101 permit tcp any any eq pop3                                          
access-list 101 permit tcp any any eq https
Question by:Jaceallan
LVL 28

Accepted Solution

batry_boy earned 500 total points
ID: 20337235
Here are the commands to allow those 3 ports inbound:

access-list 101 permit tcp any any eq smtp
access-list 101 permit tcp any any eq 143
access-list 101 permit tcp any any eq 993
access-group 101 in interface outside

Now, having said that, there's one other aspect that we haven't covered here and that is that those commands above allow inbound traffic on those 3 ports to ANY destination, which I don't recommend.  I would identify the specific hosts on your network that you want to allow that traffic to, create static translations for them and then put in the commands above referencing those specific destination hosts.

For instance, say you have a single SMTP server that you want to allow those ports inbound to and it's internal IP address is  You also have a public IP address assigned to you by your ISP of (just an example, of course).  You will need to translate to a public IP ( so that Internet traffic can be initiated to that host since that public IP is routable across the Internet and is a private class address that is non-routable.

Assuming all of the above info, here is the list of commands you would put in to achieve that configuration:

static (inside,outside) netmask
access-list 101 permit tcp any host eq smtp
access-list 101 permit tcp any host eq 143
access-list 101 permit tcp any host eq 993
access-group 101 in interface outside

The first command above establishes the static translation between and
Commands 2-4 configure any Internet host to send traffic to host (that will then be translated into when it is allowed inbound to the inside interface) on those 3 ports.
The last command applies the access list "101" to the outside interface in an inbound direction.

Hope this helps...

Author Closing Comment

ID: 31410900

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