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dorianj / CoRD

CoRD is a Mac OS X remote desktop client for Microsoft Windows computers using the RDP protocol. It's easy to use, fast, and free for anyone to use or modify.
http://cord.sourceforge.net/
346 stars 135 forks source link

Sometimes it does't connect #52

Closed falarcomph closed 10 years ago

falarcomph commented 10 years ago

Somedays I can't connect to many servers. For exemple, today I can't connect to some server here, but I could yesterday, and today, I can connect using Remote Desktop Connection da Microsoft.

Thanks

jonnyyu commented 10 years ago

I met the same problem, using 0.5.7 on Mavericks and try to connect to a Win8.1 system. RDP can connect but CoRD can't.

voxx commented 10 years ago

I'm having this same issue.

Mavericks // 0.5.7 // Windows Server 2K8 R2 Ent

I can connect to 20 of 22 servers all using the same exact configuration and deployed from the same VM image. The first 20 connect with absolutely no issues, the last 2 refuse to connect and just time out unexpectedly before reaching the login screen. There is absolutely nothing different about the configuration on the cord client or serverside among these servers, yet the CoRD client refuses to connect to two of them. I've spent hours scanning the web for a fix, and testing different configurations client and server side and I'm completely stumped.

Windows RDP connects just fine to these servers, as does CoRD on previous version of OSX.

Why was this issue closed? It appears there are numerous people experiencing the same issue?

peelman commented 10 years ago

This issue hasn't been closed...there's just nobody actively working on CoRD right now. If you haven't, try grabbing the latest source and building and running that. There have been several patches submitted by generous users who have resolved a few issues here and there.

I haven't found a server that I can't connect to yet and I've been running Mavericks since one of the early betas; if I do at some point I might dive into it and see what is going on, but for the moment, that's time I can't spare (nor apparently can @dorianj). We accept patches and pull requests all the time, but this hasn't been an issue any of the random hoards has been able to fix it seems.

voxx commented 10 years ago

Hey Peelman,

I've built from the latest source and still have the same issues unfortunately.

There are a handful of servers that it just will no longer connect to that it used to connect to just fine. If one of you could lend a hand in troubleshooting it would be greatly appreciated as I use this app on a daily basis and I'm going to have to start looking for a different RDP client if I can't get this resolved.

I'd be happy to provide you with a couple servers that I have confirmed on multiple computers running Mavericks that refuse to connect, that appear to connect just fine with other versions of OSX.

Thanks! -VoxX

peelman commented 10 years ago

Test servers isn't the problem. Time and energy are much more important.

I started working on CoRD because things were broken for me and I wanted them fixed. If/when a similar situation arises again, I'll probably do what I can to fix it. Until then, I don't have the justification to spend the time on it, but I'll continue to encourage others to contribute whatever they can.

kiddailey commented 10 years ago

I'm posting this response here (as well as on the Windows 2012 connection problem issue #44) in case it helps in this particular case.

Not sure if it's related, but I was having a similar issue trying to connect to 2008 SP2 and was able to resolve it in a surprising way. I had two servers that (essentially) are the same configuration. CoRD could connect to both just a while back, but suddenly one stopped working. RDC connected fine to both.

I noticed that on the one that wasn't working, CoRD was triggering a DNS lookup, but then there would be no visible network activity to the server. With the machines that did work, I saw the DNS lookup followed by an immediate attempt to connect to the server.

After seeing the DNS requests, it dawned on me: I'm using IP addresses to connect

I suspected something about the unnecessary DNS lookup response was causing the issue. And looking at the DNS responses for a few servers that worked and comparing it to the one that didn't, I found a telling result:

Working servers:

Non-working server:

CoRD appears to be trying to connect to the reverseDNS address, which fails. Coincidentally, RDC does not issue a DNS lookup when connecting via IP.

I didn't need the reverseDNS record for this particular IP so I removed it, flushed my DNS cache and waited a bit.

I can now connect to both servers with CoRD.

Unfortunately, I can't explain why it worked and then stopped. I can only assume that my ISP added the reverseDNS at some point, or something about CoRD in OS X Mavericks doesn't like it. In any case, it seems the fix for CoRD in my particular case is to either not do DNS lookup for IP address connections or figure out how to handle reverseDNS better.

Hope this info helps someone else :)

dadaz commented 10 years ago

Yeaah you saved my day ! Thanks

It works. I was having different name in DNS and in reverse DNS for an server, no it works whooo !

You're my hero ;o)

kiddailey commented 10 years ago

Glad it wasn't just me and that the solution has effectively been proven. You're welcome :) I haven't had any additional issues with connecting since my post as well.

voxx commented 10 years ago

kiddailey - You've stumbled across the issue.

It's related to ReverseDNS record and how mavericks is handling them.

I've narrowed down all the servers I was having issues connecting to and found that there was an improper reverse dns ptr record associated with the primary ip address of the server which I was attempting to connect to.

Either removing the incorrect reverse dns ptr attached to the ip, or updating it to the proper fully qualified domain name has 100% corrected the issue.

Every server that didnt have a reverse ptr record associated with the primary ip connected fine before and still does.

Every server that had a reverse ptr record associated with the primary IP that was incorrect was failing to connect, and after fixing them, they all connect properly now.

Thanks for the nudge in the right direction, i can now get rid of the clunky microsoft rdc client, and go back to using my cord setup :)

-VoxX

viktor-evdokimov commented 10 years ago

I noticed that CoRD can't connect when option "Allow connections only from computures running Remote Desktop with Network Level Authentication" is turned on. Turning off this feature resolved my issues with CoRD not being able to connect.

damancuc commented 9 years ago

how can I remove reverseDNS record for the particular IP or how can I fix it ?