Solved

Restricting smtp traffic to specific IP address ranges PIX 506e

Posted on 2011-03-22
5
769 Views
Last Modified: 2012-05-11
We used to have our spam filter on the inside network; now we have outsourced to an outside spam filtering company.  Our current setting is to allow all smtp (port 25) traffic through our firewall to our Exchange 2003 server.  

I want to restrict all smtp traffic through the PIX 506 except from the following WAN IP address ranges:

194.116.198.0/23 (194.116.198.0 to 194.116.199.255) subnet 255.255.254.0
208.87.136.0/23 (208.87.136.0 to 208.87.137.255) subnet 255.255.254.0
203.100.58.0/24 (203.100.58.0 to 203.100.58.255) subnet 255.255.255.0

current Pix access list entry is:

access-list acl-out permit tcp any interface outside eq smtp

I'm just a bit rusty on adding the ranges.
0
Comment
Question by:techcontracting
5 Comments
 
LVL 4

Expert Comment

by:m_walker
ID: 35195809
I cant remember which why it is on the pix.
My 3750 does it this way
access-list 110 permit tcp 172.30.0.0 0.0.255.255 any eq 22 log

so I would try

access-list acl-out permit tcp <network> <pattern> interface outside eq smtp
eg: for 194.116.198.0/23
/23 = 23 bits = pattern (not mask) 0.0.1.255
access-list acl-out permit tcp 194.116.198.0 0.0.1.255 interface outside eq smtp

203.100.58.0/24
access-list acl-out permit tcp 203.100.58.0 0.0.0.255 interface outside eq smtp

just check with the ? when you get to the "mask/pattern" and see if it wants a match pattern or subnet mask.
0
 
LVL 6

Accepted Solution

by:
Draxonic earned 500 total points
ID: 35196104
http://www.cisco.com/en/US/docs/security/pix/pix63/command/reference/ab.html#wp1067755

access-list acl-out permit tcp 194.116.198.0 255.255.254.0 interface outside eq smtp
access-list acl-out permit tcp 208.87.136.0 255.255.254.0 interface outside eq smtp
access-list acl-out permit tcp 203.100.58.0 255.255.255.0 interface outside eq smtp

0
 
LVL 79

Expert Comment

by:lrmoore
ID: 35197703
PIX always uses subnet masks for access-lists, where routers and IOS based switches always use wildcard masks.
Don't forget to remove the acl entry permitting any interface outside eq smtp
 no acl-out permit any interface outside eq smtp
0
 
LVL 4

Author Comment

by:techcontracting
ID: 35204089
Hey guys thanks for all your help... I had the config in there except I had "tcp host" instead of just "tcp";  thanks for the clarification... works like a dream.

Thanks again,
Shawn
0
 
LVL 4

Author Closing Comment

by:techcontracting
ID: 35204095
Worked great... thanks!
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Cisco USB console Windows 8.1 unable to open serial port 4 44
Interface traffic report in FortiAnalyzer 1000D 4 26
VLAN Question 13 45
What is an ASP Table on a Cisco ASA? 3 24
Network traffic routing plays key role in your network, if you have single site with heavy browsing or multiple sites, replicating important application data from your Primary Default Gateway ,you have to route your other network traffic from your p…
Use of TCL script on Cisco devices:  - create file and merge it with running configuration to apply configuration changes
Both in life and business – not all partnerships are created equal. As the demand for cloud services increases, so do the number of self-proclaimed cloud partners. Asking the right questions up front in the partnership, will enable both parties …
Both in life and business – not all partnerships are created equal. Spend 30 short minutes with us to learn:   • Key questions to ask when considering a partnership to accelerate your business into the cloud • Pitfalls and mistakes other partners…

828 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question