Solved

ASA Shunning internal IP

Posted on 2016-10-12
10
30 Views
Last Modified: 2016-10-12
Every once and awhile our email filter gets shunned by our ASA. Doing a no shun 192.168.0.208 fixes it, but I'm not sure why it is being shunned at all since the Threat detection is set to exclude the 192.168.0.0/23 subnet (see image).capture
0
Comment
Question by:bhieb
  • 5
  • 5
10 Comments
 
LVL 28

Expert Comment

by:Jan Springer
Comment Utility
Sometimes mail servers generate a lot of traffic.  Either adjust the threat detection or exclude that IP.

And check that it hasn't been compromised.
0
 

Author Comment

by:bhieb
Comment Utility
The ip should be excluded per the screenshot, the whole subnet is.
0
 
LVL 28

Expert Comment

by:Jan Springer
Comment Utility
I see the screenshot but it apparently isn't.

Is the exclusion visible in CLI?
0
 

Author Comment

by:bhieb
Comment Utility
What is the cli command I can check.
0
 
LVL 28

Expert Comment

by:Jan Springer
Comment Utility
sh run | i shun

You should see:

threat-detection scanning-threat shun except ip-address 192.168.0.0 255.255.254.0
0
Threat Intelligence Starter Resources

Integrating threat intelligence can be challenging, and not all companies are ready. These resources can help you build awareness and prepare for defense.

 

Author Comment

by:bhieb
Comment Utility
show shun returns nothing
0
 

Author Comment

by:bhieb
Comment Utility
threat-detection scanning-threat shun except ip-address 192.168.0.0 255.255.254.0

It appears to be excluded.
0
 
LVL 28

Accepted Solution

by:
Jan Springer earned 500 total points
Comment Utility
We must have posted at the same time.

I have never seen an excluded IP get put on a shut list.  Having said that, I don't exclude subnets.

I would recommend adding the mail server IP with a /32 mask to see if that corrects the issue.
0
 

Author Comment

by:bhieb
Comment Utility
I agree it is really weird, and it has been well over a year since I last touched the firewall and this config has not changed. I think I have smartnet on it, so I can just log a ticket and make them fix it. I'm sure I'm due for an os upgrade as well.

Was just hoping it was something easy.
0
 
LVL 28

Expert Comment

by:Jan Springer
Comment Utility
It might be that it's a bug when working with a subnet.

Also, there have been several security vulnerabilities -- make sure that you get a release that covers them all and stays within the same train so that you don't have to buy more memory (if you're running something older).
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.

Join & Write a Comment

If you have an ASA5510 then this sort of thing would be better handled with a CSC Module, however on an ASA5505 thats not an option, and if you want to throw in a quick solution to stop your staff going to facebook during work time, then this is the…
Exchange server is not supported in any cloud-hosted platform (other than Azure with Azure Premium Storage).
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…
When you create an app prototype with Adobe XD, you can insert system screens -- sharing or Control Center, for example -- with just a few clicks. This video shows you how. You can take the full course on Experts Exchange at http://bit.ly/XDcourse.

763 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

Need Help in Real-Time?

Connect with top rated Experts

10 Experts available now in Live!

Get 1:1 Help Now