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For cPanel & WHM version 64

My server is under a SYN attack. What can I do?

If you believe that you are under a SYN attack, run the netstat -an |grep :80 |more command.

A list that is similar to the following example will appear, with several hundred entries: 

tcp        0      0 12.34.56.78:80        211.48.6.244:1048       SYN_RECV     
tcp        0      0 12.34.56.78:80        128.223.93.135:1167     SYN_RECV     
tcp        0      0 12.34.56.78:80        194.15.197.170:1192     SYN_RECV     
tcp        0      0 12.34.56.78:80        199.155.53.109:1039     SYN_RECV     
tcp        0      0 12.34.56.78:80        4.168.188.28:1048       SYN_RECV     

If your kernel was built with syncookie support, run the echo 1 > /proc/sys/net/ipv4/tcp_syncookies command as the root user.

Can I add SSL Certificates to an addon domain when the main account already has one?

Yes. For more information, read our SSL certificate documenation.

How can I view the contents of my SSL certificates? How can I know whether my SSL certificate and key paired correctly?

To view the contents of a certificate, run the openssl x509 -noout -text -in filename.crt command.

To view the contents of a private key, run the openssl rsa -noout -text -in filename.key command.

If the modulus number and exponent of the certificate and key match, they paired correctly. If not, they are mismatched and Apache cannot start with SSL enabled.

Google Search brought me to your site. Do I have the QHOSTS virus? How do I remove it?

If you were brought to this site inadvertently after you used a search engine, your system may be infected with a virus that affects Windows machines and forwards them to a server that it replaced with a blank cPanel server.

For more information on this virus, and methods of removal, visit the following sites:

Check these sites before you contact cPanel.

Additional documentation