Date: Sat, 6 Oct 2001 19:17:39 +0200 From: bert hubert <ahu@ds9a.nl>
(top-posting due to length of original post) Alas, the "after your TTL expires" is a killer. I don't want to resurrect a thread that has been covered in the past couple of months, but DNS just doesn't cut it for failover. Furthermore, fast DNS response != fast HTTP response. {Swamp space|non-Verio filtering policies} and BGP are the way to approach this. For redundant DNS at a single site, IP and MAC takeover are what one wants. All IMHO. Eddy --------------------------------------------------------------------------- Brotsman & Dreger, Inc. - EverQuick Internet Division Phone: +1 (316) 794-8922 Wichita/(Inter)national Phone: +1 (785) 865-5885 Lawrence ---------------------------------------------------------------------------
The really neat thing is that you can do this with any nameserver. Install N nameservers and connect each of them to one of your ISPs. These nameservers are all masters, and all contain different data.
Each one responds with data relevant for the IP addresses of that ISP. If all your links are up, people will get mixed responses. If one ISP is down, that nameserver will stop answering, and hence after your TTL expires, no requests will be made for those IP addresses.
It gets even better - recursing nameservers have the habit of locking in to nameservers that respond quickest. So you even get some loadbalancing awareness.
We operate nameservers in the US and in Europe, and we definitely see this effect.
Date: Mon, 21 May 2001 11:23:58 +0000 (GMT) From: A Trap <blacklist@brics.com> To: blacklist@brics.com Subject: Please ignore this portion of my mail signature. These last few lines are a trap for address-harvesting spambots. Do NOT send mail to <blacklist@brics.com>, or you are likely to be blocked.