The requirement to run two nameservers comes from §4.1 of RFC 1034, and is indeed for redundancy. There are numerous providers who will offer you very cheap “secondary DNS” service where they transfer the zone file from your primary server using AXFR. For example, in the UK we have a well-known provider who’ll do secondary … Read more
No, as long as both sets of nameservers have the same records you’ll experience no downtime.
Ok it seems I can now give a rough answer to my own question. Anurag Bhatia says that there exist two methods how a CDN works: DNS Have DNS to do the magic i.e when users from network ISP A lookup for cdn.website.com, they should get a unicast IP address of Cache A in return, … Read more
If you don’t want to create another IP, then all you can do is install a reverse http proxy on the main IP and a name based virtual host to route the traffic using mod_proxy. Here is how you can do it with apache, almost any http server can do it, other popular alternatives are … Read more
There are two ways that a domain name => DNS server map can be constructed: Zone file access: some registries grant access to their zone files to their registrars and other entities. This makes it pretty easy to determine which domains in those zones are delegated to a given DNS server. This is how DomainTools.com … Read more
You’re right, the main disadvantage of using a low TTL is that you’ll end up dealing with a higher query load than with higher TTL. That said, as long as your DNS host doesn’t have any problems with handling the additional load, then go ahead. Honestly, if they had concerns about their ability to handle … Read more
I’ve worked with djbdns in the past and currently run a bunch of BIND servers. The biggest problem with djbdns is best put the way my first grade teacher put it on my report card: “doesn’t play well with others”. It simply doesn’t behave like anything else on a unix box in all sorts of … Read more
They’re 13 highly available clusters of servers, not simply 13 servers. Among other things, root nameserver operators are required to have enough capacity to handle three times their normal traffic load (RFC 2870). This leads to rather large clusters. However, the root nameservers only serve responses for the top level domains themselves, i.e. com., net., … Read more
Let’s break it down a little. The NS records in the TLD zone (for example, example.com NS … in com) are delegation records. The A and AAAA records in the TLD zone (for example, ns1.example.com A … in com) are glue records. The NS records in the zone itself (that is, example.com NS … in … Read more
Nothing 🙂 http://en.wikipedia.org/wiki/BIND named is just an alias of BIND.