Disable SIP Inspection on Firepower through FlexConfig

Occasionally you may come across issues with SIP inspection on an ASA or Firepower, leading to problems with SIP/RTP voip audio. As a troubleshooting step, it’s often helpful to disable SIP inspection for testing.

Please read this note from Cisco on disabling SIP inspection to verify you everything in order before doing so:

You would typically disable SIP only if the inspection is causing problems in the network. However, if you disable SIP, you must ensure that your access control policies allow the SIP traffic (UDP/TCP 5060) and any dynamically allocated ports, and that you do not need NAT support for SIP connections. Adjust the access control and NAT policies accordingly through the standard pages, not through FlexConfig.

For Firepower devices managed by an FMC, here are some quick instructions to push out a FlexConfig policy to disable SIP inspection.

In FMC, navigate to Devices > FlexConfig

Click the Pencil icon to edit your FlexConfig device policy. If you don’t have a policy yet click New Policy to create one.

In the FlexConfig policy click the New FlexConfig Object.

Give a name a name and description for the new new object and in the text field copy the commands below (note the indentations). Click Save.

policy-map global_policy
class inspection_default
no inspect sip

Under available FlexConfig find the new object we created, highlight it, and click the left arrow to add it to the policy.

With the new object added to the policy, save the policy and deploy to your FirePower.

SSH to the Firepower and run the following command to verify that SIP is no longer in the inspection list:

show run policy-map | beg global_policy

policy-map global_policy
 class inspection_default
  inspect dns preset_dns_map
  inspect ftp
  inspect h323 h225
  inspect h323 ras
  inspect rsh
  inspect rtsp
  inspect sqlnet
  inspect skinny
  inspect sunrpc
  inspect xdmcp
  inspect netbios
  inspect tftp
  inspect icmp
  inspect icmp error

Usernames No Longer Appear in Firepower Management Center After Upgrading to 6.0

After upgrading our Firepower Management Center to 6.0, we noticed that usernames were no longer populating in our dashboards. Instead of showing users, all we could see was “No Authentication Required.”

sf-usernames01After opening a support case, TAC pointed me to the following bug: cscux39125 (cisco login required).

To resolve the issue we need to set the active directory domain to our domain’s NetBIOS short name in Firepower’s realm configuration.

To change your realm configuration go to System -> Integration -> Realms

Click Edit

sf-usernames02Go to Realm Configuration and edit the AD Primary Domain field to your domain’s NetBIOS short name.

sf-usernames03For more information see the following support forums post: https://supportforums.cisco.com/discussion/12879381/sourcefire-60-firesight-mc-60-users-not-populating

Installing a CA Signed SSL Certificate in SourceFire Defense Center 6.0

I don’t know about you, but self-signed certificates seem to trigger my IT OCD. When possible, I like to replace self-signed certs with one signed by our Active Directory CA. Here are the steps involved to replace the self-signed certificate on Cisco’s FirePOWER Management Center/SourceFire Defense Center with one signed by your internal Active Directory Certificate Authority.

  • In Defense Center, go to System -> Configuration -> HTTPS Certificate
  • Click “Generate New CSR”


  • Fill out the Certificate Signing Request information, paying attention to the common name field. The common name should match the address you use to access defense center, e.g., defensecenter.domain.org


  • Click generate, and copy/paste the certificate request output to notepad


  • Next, navigate to your Certificate Services website and click “Request a Certificate”


  • Click “Submit an advanced certificate request”


  • Under “Saved Request,”paste your certificate request output from earlier and select the Web Server certificate template. Click Submit


  • Download your newly generated certificate (Base64 encoded) and open it with your text editor of choice


  • Copy the output of your cert and go back to Defense Center. Navigate to System -> Configuration -> HTTPS Certificate
  • Click Import HTTPS Certificate and paste your certificate information into “Server Certificate”



  • Click “Save” and you should now see your new certificate installed.
  • Reload Defense Center and you should now trust the web server (assuming of course you trust the root CA)