I have a problem sending emails (API HTTP request - .Net Core) using Mailgun from the server.
If I am using the localhost, then the emails are being sent correctly but as soon as I publish the app on the server and try to send the email I get (The SSL connection could not be established, see inner exception.)
I am not sure if it’s a server SSL issue, Mailgun issue or Cloudflare issue.
I wonder if someone faced this issue before.
I spend the last 3 days (a few hours a day) trying to fix this issue but I am not getting anywhere.
Cname is: email.descod.net
Thanks
this issue was fixed by publishing the SSL certificate 1 more time and restarting the server (I think the restart did the trick)
Related
we have a C# .NET 4.5 desktop application which was released half a year ago and ran fine until today.
On start-up the app sends a JSON request to our Web API but it fails with
{"The request was aborted: Could not create SSL/TLS secure channel."}
I have found some other topics where the solution was this:
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
It works for our app as well but the big question remains:
Why did it work on thousands of computers for half a year?
The first thing I thought of was: Daylight Savings Time, the time change happened today. So I've checked the server time, renewed the SSL certificate and rebooted the server but the problem remains.
Any ideas?
App:
.NET 4.5
Server:
Ubuntu 16.04.2 LTS
nginx/1.11.10
Update
After disabling Cloudflare for the domain, the issue is gone. I don't know what exactly causes this but I suspect that it has in fact sth. to do with DST time zone and SSL handshake.
We have exactly the same issue.
Appears Cloudflare dropped supporting TLS 1.0/1.1 this morning (in our case).
I've raised this to Cloudflare. But no response from them yet.
Meanwhile I asked question in their community (https://community.cloudflare.com/t/was-the-tls-1-0-1-1-not-supported-since-4am-utc-2017-10-30/7586/3). There're other users impacted too.
My initial thoughts was DST, but today is the second day after DST switch, plus our server/client runs on the same server, using UTC. So it can't be due to a DST issue (unless something in Cloudflare internally)
The solution for now is like what you did, force client to use TLS 1.2+
I have spent hours trying to get the .NET FtpWebRequest library to communicate with my Ubuntu 16.04 FTP server using vsftpd over SSL.
No matter what I try, I always end up with the exception "A call to SSPI failed. The message received was unexpected or badly formatted."
I have tried generating client and server certificates, installing them in windows, loading them with the X509 class in .NET, toggling various client and server side options. No matter what I do, it's always the same error. I believe this has something to do with my certificate not being verified by an authority. Here are my basic questions:
1) Can .NET just ACCEPT a suspicious certificate?! Installing it 30 different ways seems to have no affect?
2) What does "a call to SSPI failed" really mean? I've read conflicting answers. I have no problem connecting with TLS/SSL via FileZilla, but .NET 4.5 just won't have it.
3) Can someone give the minimum amount of steps to have a Windows 7 client using the .NET framework connect to a Linux server using vsftpd over SSL? I strongly believe the problem lies in my Windows/.NET settings since FileZilla on my Windows machine has no problem connecting.
Thank you in advance.
Insert the line below in your vsftpd.conf:
ssl_ciphers=AES128-SHA
Created .net custom tcp server and client using tcplistener. Taks is simple to exchange the data. I have Windows server, on which I am able to communicate. Within network also I am able to communicate. When I deploy this same on our web server, public IP is not accepting connections. At client side it throws time out error:
A connection attempt failed because the connected party did not
properly respond after a period of time, or established connection
failed because connected host has failed to respond .....
Trace route shows request is going there till server and at the end its not showing time out. Server is VM on azure.
Add the endpoint to the Azure configuration:
https://azure.microsoft.com/en-us/documentation/articles/virtual-machines-set-up-endpoints/
Thanks for your help. It was firewall issue. It is resolved but I am clueless about the problem. Firewall ports opened earlier did not worked. so I stopped firewall and I found its working. later on I started and firewall it again worked. strange....fire wall is not updated it seems.
Thanks.
Kishor
I have an ASP.Net MVC application that I have added SignalR to. After following the "Getting Started" tutorial (with modifications of course since it's going in my application) I got it working on localhost. However once it's in the production environment, I get the following error:
WebSocket connection to 'ws://xxxxx/signalr/connect?transport=webSockets&clientProtocol=1.5&connectionToken=xxxxx' failed: Connection closed before receiving a handshake response.
I can access /signalr/hubs (I get a js file). Any ideas as to why this would happen?
This may be due to the fact that your web server doesn't support WebSockets (IIS 7.5, for instance. It may also be due to the fact that you are using a "proxy" server like ARR and it just cannot "route" WebSocket requests.
The first thing I would try to do is to disable WebSockets on SignalR, just as a debug tool. Here's how: SignalR - How do I disable WebSockets
If your problem persists, it's a general SignalR problem but at least you will have a more specific error. If the problem stops, now you know it is a server issue.
We recently migrated a site to a new server. This site integrates with Barclaycard ePDQ, and was working fine on the old server.
Since migrating, however, ePDQ is unable to hit our Postback Url (which is an ashx handler). They are seeing a response http code = -1, which we're told means it's either exceeding the maximum timeout (20 seconds) or the url simply can't be accessed.
We checked the firewall on the new server, and it is allowing incoming traffic over ports 80 and 443.
I am also able to mimic the POST with the same request data to the Postback Url using Fiddler, and this works fine. So no timeouts, and it is accepting POST requests over port 80.
The site was migrated several days ago, and running a DNS propagation tool against the domain shows it universally resolving to it's new IP.
We're running Windows server 2012 on the new server. The old server was running Windows 2008 R2.
Does anybody have any ideas why ePDQ is unable to hit our postback url?
Thanks in advance