Category Archives: Uncategorized

Duplicate ipv6 global 2001 address issue . Redhat

IPV6 test case

If we set a static ipv6 and IPV6_AUTOCONF was set to yes. the IPV6_AUTOCONF value will not take affect until we bring down the interface and bring it back up. Performing a network restar will not change the value of IPV6_AUTOCONF.. We have found that after a restart of the network service. The interface receives a second global 2001 address.

steps to duplicate

1. Add IPV6ADDR=
2. IPV6_AUTOCONF=yes change to no
3. restart the network manager or service

4. if you want to set the default gW use IPV6_DEFAULTGW= . This may be requires as router advertisements will be disabled. RA is required to received the GW information from the router.

Possible fix is to restart the interface or the below.
Set net.ipv6.conf.eth0.accept_ra to on in the sysctl file and set autoconf to off.

net.ipv6.conf.eth0.autoconf = 0

net.ipv6.conf.eth0.accept_ra = 1 << enable router advertisments /sbin/sysctl -a | grep net.ipv6.conf. << check settings

Apache2 upgrade to 2.4 on Debian 8

While upgrading our last Debian 7 server. I swear I must of missed something during the upgrade. I received multiple apache errors and our websites failed to load.

Error 1
AH00526: Syntax error on line 74 of /etc/apache2/apache2.conf:
Invalid Mutex directory in argument file:${APACHE_LOCK_DIR}

Fix source /etc/apache2/envvars
/usr/sbin/apache2 -V
/usr/sbin/apache2 -t


Error 2
Invalid command ‘SSLMutex’, perhaps misspelled or defined by a module not included in the server configuration AH00526: Syntax error on line 77 of /apache/conf/ssl.conf:

Replace SSLMutex with

” Mutex sysvsem default ” without the quotes

Error 3
Error: “Invalid command ‘Action’, perhaps misspelled or defined by a module not included in the server configuration”

Fix: The actions module need to be enabled
” a2enmod actions ”

Error 4
mode_rewrite error

Fix: a2enmod rewrite

Error 5
403 Forbidden

This error really was confusing. Before the upgrade apache permissions were fine. After reading .

I had to change
2.2 configuration:

Order allow,deny
Allow from all

2.4 configuration:

Require all granted

Fedora 24 – Kernel upgrade 4.7.3 Virtualbox

Fedora pushed down kernel 4.7.3 to production. The sad part about this was that we received the error “A start job is running for udev wait for Complete Device….” after rebooting. After a hour of troubling shooting. The issue was related to VirtualBox 5.0 . We thought we were running the latest version of VirtualBox . But they have moved on to version 5.1.x . So after upgrading virtualbox and guest additions. The error cleared and the system booted without any issues. I dont expect to see the same issue on physical machines.