Home / server / Questions / 413514
Accepted
ledy
Asked: 2012-08-02 22:19:13 +0800 CST

DNS workaround for webhost DDoS [duplicate]

  • 772

My webhoster seems to have some troubles with DDOS attacks and routing overload. This makes my IP to be not available sometimes and I'd like to add a failover IP for the domain.

However, 2 A-Records means that it's similar to a load balancer which is NOT what i am looking for. I do not want the fallback machine to be accessed any time - except in case of real troubles or downtime of first choice IP.

Is there a out-of-the box solution that allows me such a failover ip?

If not, if it requires a DNS re-configuration: Is there a recommended script or similar that can be run on the secondary machine (of course, this is with a different hoster). This has to check whether the first choice ip is down and must overwrite the A-record, right? This requires my domain hoster to provide an API for the DNS settings...

networking

1 Answers

  1. Best Answer

    Any DNS provider that supports Dynamic DNS can assist with this requirement.

    Let's assume you use DynDns and get a dynamic DNS name of uptime.homeunix.comNote 1. Assume your DynDns username is foobarme, and your password is "LeTmeiN"

    • Assume the address of your primary webhost is 192.0.2.100
    • Assume the address of your backup webhost is 192.0.2.200
    • Assume your web service's address is http://solid.rock.local/

    Use ipcheck.py to assign your primary address to uptime.homeunix.com (I'm using linux)...

    $ python ipcheck.py -a 192.0.2.100 foobarme LeTmeiN uptime.homeunix.com

    Now CNAME solid.rock.local to uptime.homeunix.com.

    If you need to use the backup webhost, it's this easy...

    $ python ipcheck.py -a 192.0.2.200 foobarme LeTmeiN uptime.homeunix.com

    The DNS TTL on these DynDns DDNS records is typically one-minute... pretty low.

    Note 1: BTW, uptime.homeunix.com is available right now if you like it :-)

    • 1