[quote]But, you mean an IP that is unique AND static. Si
no. we just guarantee that it’s unique. we try not to change them often
but there is no guarantee that we won’t change it. this doesn’t mean that
it’s dynamic (ie we’re not changing it every week or anything) but if we
were to move you to a machine at a different location we’d have to change
it (for example).
Gotcha… But I don’t recall seeing that at other hosts. Generally, when you pay for an IP number, you pay for a static one. If moves are made, the number moves with you. Machine moves are usually within the same data center, so it’s usually not a problem.
well if our nameservers were down, a site with a unique IP would go down
still unless you knew the IP address and typed it into your browser.
And that’s exactly what I do…
i do know a few IP addresses by heart (my home computer, my work computer,
my mail server etc. etc.) i don’t as a general rule make a practice of
Me neither. That’s why I tend to write them down.
I have seen DNS problems (Net-wide and more local to another host) last for a day or more, during which I was able to continue working on a website under development by using the IP number. If I hadn’t had a static IP number (at least static for that period of time), I would have lost those days of development time.
Naturally, the public generally won’t know the IP number of a certain site, but if you’re working on a site, or others you work with need access when DNS is down, that number is important.
uniqueness/staticness. Thus the confusion
hrmm well that’s not how i meant it. the domains are assigned an IP
address. however other domains are also assigned the same IP address.
That’s clear now. Thanks.
the multihoming I was talking about takes place. Non?
well i’m still not sure what you mean by ‘multihoning’. the sharing would
not be where the problem was though.
[quote]no. most domains share an IP with a number of different domains, and this
IP address doesn’t change often. this is not the cause for the problems
you’re describing however.
each machine has about 20 or so webservers, and each webserver has a
unique IP. each of these webservers has (i’m just guessing) 30 or so
domains on it. this number could be more or less. so probably about 30
domains share one IP address.
And that’s what is called “multihoming”, IIRC (the admins may call it something else, but from what I understand, that’s what it’s called). Multihoming is when single IP number serves more than one machine, or more than one domain on a machine.
And… Yes, from what I can see, this would have to be where the problem lies.
Once you get past the DNS stage, and past the IP stage, you’re into multihoming. If the server is reachable by IP number and by regular DNS using machinename.dreamhost.com, but isn’t reachable via example.com, the only stage that’s left is the multihoming setup. That’s the stage – the “name-based hosting” stage – at which requests coming into a single IP, but for different domain names, are guided to the proper machines and/or directories for those domains.
[quote]if i type ‘ftp yourdomain.com’ or ‘ftp mydomain.com’ we can both ftp to
the same IP address at the same time if these two domains share an IP
address. Mail and web stuff are the only points where a translation must
be made; however this is trivial (unless you’re using a really, really,
really old browser that doesn’t support name based virtual hosting).
i hope that makes sense sort of… it’s difficult to explain.
No, you’ve explained it clearly this time.
But I do believe you’re mistaken about multihoming not being the problem. As far as I can tell, it’s the only possible point of failure. Whether it’s a hardware problem, an NFS problem, or whatever, it’s ocurring during the multihoming stage.
What else could it be, given the symptoms?
(BTW-- Let me know if you want to take this conversation to another forum…)