How to prefer IPv4 in Linux?
In Linux with IPv6 and IPv4 (dualstack), IPv6 address have preference. This can be easily changed in file /etc/gai.conf, add lines # /etc/gai.conf precedence ::ffff:0:0/96 100… Read More »How to prefer IPv4 in Linux?
centos
Protecting WordPress with mod-security
This my blog and also other hosted websites running WordPress are target of bots trying passwords to wordpress admin and posting spam comments. I was unable to found simple plugin for comments dns blacklist, so I focused to mod-security. Read More »Protecting WordPress with mod-security
Installing vSphere cli on Centos 6
VMware vSphere cli requires many CPAN libraries. On Centos 6 I have enabled EPEL repository and installed packages:
Read More »Installing vSphere cli on Centos 6
Redhat Enterprise Linux 6 IPSec configuration example
IPSec implementation has been changed in recent Redhat Enterprise Linux (RHEL) from ipsec tools (used in RHEL 5) to openswan in RHEL 6. Configuration using ifcfg-ipsec interfaces doesn’t works any more. Obviously, same change applies for Centos.
Read More »Redhat Enterprise Linux 6 IPSec configuration example
Install conntrack tools on Centos 5
Conntrack tools allows manipulating linux connection tracking table. Command conntrack is useful for deleting conntrack entries, but it is not included by default in RHEL/Centos.
Read More »Install conntrack tools on Centos 5
Digmia Centos repository
Digmia Enterprise Linux Source is repository with many interesting and actual packages for Centos (RHEL). It contais for example mysql-5.0.84-2.el5.x86_64.rpm, php-5.2.10-2.el5.x86_64.rpm, zabbix-1.8.3-2.el5.x86_64.rpm, postgresql-8.2.14-1.el5.x86_64.rpm and many… Read More »Digmia Centos repository
Blocking SIP brute force attacks with fail2ban
SIP brute force attacks against Asterisk servers are very popular. Best way to defend is to block sip by default and allow only allowed IPs to connect. But we can not use this approach in some cases. Here fail2ban can help.Read More »Blocking SIP brute force attacks with fail2ban