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Xip.io - a magic domain name that provides wildcard DNS for any IP address

xip.io

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Re: Xip.io - a magic domain name that provides wildcard DNS for any IP address

#81

Post by adgar »

mparlane wrote: post #80
sscheper wrote: post #73

Earlier quoted context omitted.

Bravo. I sometimes wish HN had an option to filter out 37 Signals items...

sscheper, I love your average on HN (-.2). In response to jsprinkles: I do believe this was just a hack and not exactly intended for public consumption but someone decided "hey that's pretty cool let's chuck it on the web". Which has the obvious results of the opinions of hundreds :P

This was an announcement; "someone" in this case is a co-worker of the author. The author of xip.io (sstephenson) came on thread to discuss this and a related announcement about Pow.

Re: Xip.io - a magic domain name that provides wildcard DNS for any IP address

#82

Post by riobard »

I have a dd-wrt router with DNSmasq functioning as the DNS server for local hosts. DNSmasq resolves external domains using Google DNS (8.8.8.8/8.8.4.4). With this setup, domain names like 192.168.X.X.xip.io and 127.X.X.X.xip.io won't resolve, and I believe there is something wrong with my DNSmasq setup. Anyone else ran into similar issues?

(Update) Problem solved by myself. The DNSmasq config has stop-dns-rebind option enabled, which filters out DNS results in private IP ranges from upstream servers for security reasons. DNSmasq doc has the following part:

    -stop-dns-rebind
Reject (and log) addresses from upstream nameservers which are in the private IP ranges. This blocks an attack where a browser behind a firewall is used to probe machines on the local network.

In case you run into this issue, just comment out this option in dnsmasq.conf and restart dnsmasq.

Re: Xip.io - a magic domain name that provides wildcard DNS for any IP address

#83

Post by jsprinkles »

dools wrote: post #75
colmmacc wrote: post #72

Earlier quoted context omitted.

Edge cases and niggling "works ok for me" problems really do matter for something that's intended to be used with testing. Otherwise it's easy to rat-hole for a long time trying to determine why your test isn't working, when it turns out it was a problem between your DNS resolver and an upstream domain. Problems between DNS resolvers and DNS authoritative servers are classically intermittent; they usually depend on t…

What I took away from this, though, is that they just want to be able to load a web application they're developing on their iPad/iPhone or otherwise "restrictive" device that doesn't allow you to easily make local DNS modifications (such as /etc/hosts files). I honestly don't understand what you've written above (although I re-read it a couple of times, I guess I'm just not knowledgeable enough about DNS for it to ma…

The state that xip.io is in right now could, theoretically, result in DNS failures 50% of the time on any device.

Re: Xip.io - a magic domain name that provides wildcard DNS for any IP address

#85

Post by philfreo »

beagle3 wrote: post #11

What is the use case that requires http://test.10.0.0.3.xip.io/test-page rather than http://10.0.0.3/test-page ? I've been using the latter on iphones and ipads with no problem. Honest question.

Multiple sites of course, though that can be solved with ports.

Some things are harder to do without a hostname - cookies, for instance, can be tricky.

Re: Xip.io - a magic domain name that provides wildcard DNS for any IP address

#86

Post by X-Istence »

riobard wrote: post #82

I have a dd-wrt router with DNSmasq functioning as the DNS server for local hosts. DNSmasq resolves external domains using Google DNS (8.8.8.8/8.8.4.4). With this setup, domain names like 192.168.X.X.xip.io and 127.X.X.X.xip.io won't resolve, and I believe there is something wrong with my DNSmasq setup. Anyone else ran into similar issues? (Update) Problem solved by myself. The DNSmasq config has stop-dns-rebind opti…

I run unbound as my recursive DNS resolver and it too strips those results out for security purposes.

Re: Xip.io - a magic domain name that provides wildcard DNS for any IP address

#87

Post by dguaraglia »

beagle3 wrote: post #11

What is the use case that requires http://test.10.0.0.3.xip.io/test-page rather than http://10.0.0.3/test-page ? I've been using the latter on iphones and ipads with no problem. Honest question.

I could see how it'd help if you are debugging a service that parses a subdomain out of the main URL for a particular purpose (think, for example, a SaS that provides a domain like 'yourcompany.mysasservice.com').

Other than that, ports will do.

Re: Xip.io - a magic domain name that provides wildcard DNS for any IP address

#88

Post by X-Istence »

jsprinkles wrote: post #48

I've identified several technical problems with this domain, and this isn't an example of how to properly operate DNS. 37signals is setting an absurdly low TTL on these records (10 minutes; the answers never change, I absolutely do not understand the logic behind this TTL), which means every 10 minutes you're re-resolving a local address , through a CNAME (so two DNS round trips, and in my case this resolution took b…

I find it interesting that we are required to do a second round-trip for the CNAME when it is available in the same bailiwick and could be sent as part of either the ADDITIONAL SECTION or as part of the ANSWER SECTION. Would you happen to know what the RFC has to say on this? I understand that CNAME's are not allowed to exist with other records, but returning it in the ADDITIONAL SECTION shouldn't be a cause for concern.

The reason why it may not be serving NS records for itself is because looking at what is available on Github the server is started on port 5300, so I am assuming that there is some sort of DNS resolver/cache sitting in front of it that may be stripping them out. Same thing with it not responding with "Authoritative answer" bit set...

Although that is simply speculation, maybe they did put the node service directly on the internet.

Re: Xip.io - a magic domain name that provides wildcard DNS for any IP address

#89

Post by X-Istence »

colmmacc wrote: post #68
jsprinkles wrote: post #48

I've identified several technical problems with this domain, and this isn't an example of how to properly operate DNS. 37signals is setting an absurdly low TTL on these records (10 minutes; the answers never change, I absolutely do not understand the logic behind this TTL), which means every 10 minutes you're re-resolving a local address , through a CNAME (so two DNS round trips, and in my case this resolution took b…

It's a cool idea, but there are some other problems too; which I just want to list to help the developers and am not trying to rain on a parade. As in the parent comment, a CNAME is returned for arbitrary names; % dig foo.192.0.2.1.xip.io foo.192.0.2.1.xip.io. 600 IN CNAME foo.a2eo0.xip.io. foo.a2eo0.xip.io. 600 IN A 192.0.2.1 but only if the request is of type A. Requests of other types return invalid NXDOMAIN respo…

Source code for encode/decode is found here:

https://github.com/sstephenson/xipd/blob/master/src/index.co...

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