Share This:

In Discovery 11.0 we updated nmap to version 7.01. This gives us the advantage of:

 

- better IPv6 support

- faster scans

- many other improvements

 

However, a limited number of customers have seen an issue when performing discovery on 11. This is seen in the Discovery UI as an "Execution Failure" failure on DeviceInfo. The ScriptFailure has this error:

 

Warning: Kernel filter failed: Bad file descriptor

Failed to set the pcap filter: can't remove kernel filter: Bad file descriptor

 

There are 2 issues (with nmap) here:

 

- the error handling is incorrect

- an EPERM (permissions) failure on a particular ioctl call.

 

We've found that the issue can be triggered if you are running a Virtual Appliance and using older VMware Tools - or none at all - and/or one of the older Network Adapter Types (e.g. Vlance or VMXNET < 3).

 

If you are experiencing the issue, we recommend you update (or install if you haven't) your VMware Tools to the latest available for your ESX version and set your Network Adapter Type to VMXNET 3 or Flexible (if available). If you are not experiencing the issue, we also recommend that you update/install VMware Tools . If you are not seeing the issue there is no need to change the Adapter Type.

 

We expect this should resolve your issue. If you're still seeing issues however, we have patched NMAP to gracefully handle the errors. This is available from the BMC ftp site: ftp://ftp.bmc.com/pub/BMCDiscovery11Nmap. An md5 is available with the RPM for download verification.

 

 

Instructions for installation

 

Stop discovery: Go to Manage -> Discovery and click on "STOP ALL SCANS" with a user with appropriate permissions.

 

[optional] Verify download: With both the .md5 and .rpm files in the same directory:

     $ md5sum -c nmap-7.01-2.rhel6.x86_64.rpm.md5

 

Update nmap RPM: Run the following command line as the tideway user:

     $ sudo /bin/rpm -Uvh nmap-7.01-2.rhel6.x86_64.rpm

 

Start discovery: Go to Manage -> Discovery and click on "START ALL SCANS"

 

If you have applied the above and still seeing the issue, please contact Customer Support.