"Emilia Lambros" <[EMAIL PROTECTED]> writes: > Also with DNS, you're correct - it does only respond to A records so > if you want anything more from it, you will need the SLB to sit in > front of name servers. In our case, we only required A records with > a very low ttl, so the SLB doing the job was perfect.
That's what we wanted too. The problem is that you can't control which questions it gets. Lots of clients will ask for AAAA records nowadays. A regular DNS server will immediately return NXDOMAIN when no AAAA records are defined, but the ServerIron didn't even when running as a standalone DNS server. It just dropped the AAAA requests, causing long delays for these clients before they eventually timed out and fell back to asking for an A record. Therefore, you do want to run a real DNS server behind it even if you are just serving A records. The real DNS server will generate the proper NXDOMAIN anwsers Now, I should of course add a disclaimer: This was the observed behaviour the way we configured it. We might have forgotten some crucial part. Here are the relevant parts of the config before adding a real DNS server in case anyone wants to verify it: server virtual vs 148.x.x.69 predictor round-robin port http port dns bind http real1 http real2 http real3 http real4 http gslb policy round-trip-time tolerance 0 round-trip-time cache-prefix 16 round-trip-time cache-interval 1800 dns ttl 60 dns override dns cache-proxy gslb site Site1 si serveriron1 148.x.x.67 gslb site Site2 si serveriron2 217.x.x.3 gslb dns zone glsb.example.com host-info null-host http host-info null-host ip-list 148.x.x.69 217.x.x.4 Bj?rn
