Description

During an upgrade from Junos 14.1X53-D25, 27, 30 and 40 to any Junos of QFX standalone or virtual chassis, the 'vjunos fails to install' error is seen.

Symptoms

The following error is seen on my device when trying to perform an upgrade on QFX5100:

Error: jinstall-vjunos fails post-install
Error: jinstall-vjunos-14.1X53-D34-domestic-signed fails post-install

This issue occurs if 'tcp-drop-synfin-set' and 'no-tcp-reset drop-tcp-with-syn-only' under Internet-options stanza is configured on the QFX5100 Standalone/Virtual-chassis

Solution

Step A:

Check the configuration of the system internet stanza prior to the upgrade:

# show system internet-options
tcp-drop-synfin-set;
no-tcp-reset drop-tcp-with-syn-only;

# show |display set |match  internet
set system internet-options tcp-drop-synfin-set
set system internet-options no-tcp-reset drop-tcp-with-syn-only
 
 

Delete this configuration prior to upgrade:

# delete system internet-options
{master:0}[edit]
root# show |compare
[edit system]
  internet-options {
      tcp-drop-synfin-set;
     no-tcp-reset drop-tcp-with-syn-only;
 
{master:0}[edit]
root# commit

 

After deleting this configuration, perform the upgrade on the Standalone/Virtual-chassis without any failure.

Note: Re-configure system internet stanza again after the upgrade to avoid TCP security attacks.

Step B:

If the above configuration is not available in the switch, please enter the command:
   > request system software add <Junos image >  force-host no-validate

OR

Format and install the switch. 
CAUTION: Please take a configuration backup before formatting the switch

Modification History

2019-05-13: Added alternate Step B