Dns.GetHostEntry failing on Mac but not PC?

Anyone tried using Dns.GetHostEntry in C#? Had any success?

On Windows, this call is successful and everything gets resolved. On Mac, it never seems to come back out of the call.

I read online that there was a bug in Mono but it got fixed (allegedly) in a newer version ... do we know what implementation of Mono that Unity is using?

Thanks!
Jeff.

 

I'm using the following code to test internet and it works fine on both platforms.

Code (csharp):

1. public static bool IsInternetAvailable()
2.     {
3.         try
4.         {
5.             IPHostEntry thisIPHostEntry = Dns.GetHostEntry("www.google.com");
6.             return true;
7.         }
8.         catch
9.         {
10.             return false; // host not reachable.
11.         }
12.     }

 

Ah ... seems you can't do this with an IP address. Maybe I'm missing something, but if I try Google's IP address like this:

Code (csharp):

1.  
2. public static bool IsInternetAvailable()
3.     {
4.         try
5.         {
6.             IPHostEntry thisIPHostEntry = Dns.GetHostEntry("72.14.205.103");
7.             return true;
8.         }
9.         catch
10.         {
11.             return false; // host not reachable.
12.         }
13.     }
14.  
15.  

This will fail both in the IDE and the browser.

 

Looks like a bug in Mono.

Link:
https://bugzilla.novell.com/show_bug.cgi?id=MONO79886

Dang. Ok. Since I know the IP address I need to connect to, I think we can work around this ... (goes off to dig) ..

 

But does this work for you in a webplayer? I'm getting a SocketException from this Dns.GetHostEntry call in the webplayer but it works fine in standalone and in the editor. The exception is "No such host is known". I tried my "my.address.com", "http://my.address.com", "http://my.address.com/", and the literal IP address.

 

just to bump this alive -

I'm working with gethostentry and on mac, like discussed here, it works the FIRST time in the webplayer - subsequent calls fail (after a browser refresh or leaving and coming back later). Restarting the browser entirely corrects the problem. I am currently hacking around this by caching the correctly returned results in playerprefs, and using those if the entry is incorrect. Does anyone have any more up-to-date information on this problem, or if there is something worth trying? When it fails, it is not an explicit exception - rather, only 1 ipv6 is returned that is not capable of being bound.

thanks ahead of time for any thoughts!

 

you don't need to create a host entry with ips ... the only reason to use this class basically is to get the ip because the network commands don't accept urls, just ips. (I for example use it to get the ip of master server, facilitator and connection tester from url)

 

Thanks for the idea of using PlayerPrefs as a workaround DNS cache.

 

Bump!

This is still an issue. We came to the same store in the player prefs "solution". But shame on unity for ignoring such an annoying issue.

 

Unity cannot do anything.

This is an issue with Mono, and so an external utility of Unity.

3.0 may remedy the situation depending on how Mono fixed it's bugs, but there is nothing Unity can reasonably do about it.

 

Has anyone tried Dns.GetHostByName("www.google.com")? This seems to work fine for me on the Mac (running 10.5.8). I did a web player build and ran that, seems to work multiple times in safari (running from the local html file).

 

Awesome!!! I tried a lot of ways and this worked the best! The performance is fantastic! It's awaitable!

Have tested it on Editor and Android. Will try iOS and Browser soon.