Bug ID 949477: NTLM RPC exception: Failed to verify checksum of the packet

Last Modified: May 29, 2024

Affected Product(s):
BIG-IP APM(all modules)

Known Affected Versions:
14.1.3,, 14.1.4,,,, 15.0.0, 15.0.1,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4, 16.0.0,, 16.0.1,,

Fixed In:

Opened: Sep 29, 2020

Severity: 3-Major


NTLM authentication fails with the error: RPC exception: Failed to verify checksum of the packet.


User authentication fails.


-- Start nlad process with 'encryption'. -- Configure a user, and map that user to a huge number of groups. -- Configure NTLM front-end authentication.


1. Run the 'nlad' process with '-encrypt no' in the file /etc/bigstart/startup/nlad. 2. Disable encryption for nlad: # vim /etc/bigstart/startup/nlad change: exec /usr/bin/${service} -use-log-tag 01620000 to: exec /usr/bin/${service} -use-log-tag 01620000 -encrypt no 3. Restart nlad to make the change effective, and to force the schannel to be re-established: # bigstart restart nlad

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips