Hello everyone,
I’ve been trying to set up a Mumble voice chat server on my home network using a Debian server. As part of the setup process, I need to obtain an SSL certificate from Let’s Encrypt for secure HTTPS access to the server. However, I’m encountering an error when running the Certbot client to request the certificate.
Here’s the command I’m running:
sudo certbot certonly -d mydomain.com
But I get the following error message:
Timeout during connect (likely firewall problem)
I’ve checked my firewall rules and confirmed that I’ve opened port 80 as required for the Let’s Encrypt verification process. Here’s the relevant rule in my ufw configuration:
80/tcp ALLOW Anywhere
Despite this, I’m still getting the timeout error. Has anyone else encountered this issue before? What steps should I take to troubleshoot further?
Thanks in advance for any advice!
Since this is on a home network, have you also forwarded port 80 from your router to your machine running certbot?
This is one of the reasons I use the DNS challenge instead… Then you don’t have to route all these Let’s Encrypt challenges into your internal network.
like this?You don’t need UDP on port 80 forwarded through. HTTP is TCP only.
HTTP/3 is UDP as well but only on port 443.
Maybe…? I’m not familiar with that router software, but it looks plausible to me…
Many home ISPs block port 80 and 25. You should be able to Google that and confirm. If that’s the case you’ll have to use a different method.
This is the answer. Pretty much every ISP blocks 80 They say it is because worms use it blah blah but it is exactly what you think. They don’t want you running a web server. You’re probably going to have to do the DNS challenge instead.
ISP said that it does not block port 80
Try something like https://www.webpagetest.org/ or any other “proxy” service to confirm for youself if it is publicly accessible.
to Google?
Google search “Does block port 80”
are you actually running a web server on that host? iirc, certbot will place a temporary token to be served by your web server (Apache, etc.) to show that you actually control the domain you are requesting a cert for.
I switched to DNS based retrieval as soon as let’s encrypt offered it, so its been years since I retrieved certs via http.
actually I’m not hosting any web servers currently )
if you are using http cert retrieval, certbot needs a place put the temp. token to authenticate your contrrol of the domain your are creating a certificate for. usually that will be the same webserver you want to serve the certificate from.
if you are not running an actual weberver on port 80 that certbot can insert a token for, certbot cannot complete.
this is, of course, in addition to other possible issues such as ISP port blocking - but without a web server listening on TCP/80, you will have to use other authorization methods (like DNS) to generate a cert.
what would you recommend to a newbie?
Easiest is probably “certbot --standalone” which lets certbot use its embedded webserver.
Otherwise nginx and apache httpd are common and reasonable options.
heh, forgot about the standalone web server in certbot. thats a good ephemeral option.
if you are able to run a public web server, then certificate issuance via certbot http challenge works pretty well. the web server can serve a really simple static page with little to nothing on it - but of course its another potential vector into your network.
if your public domain DNS makes use of a supported dns provider or you run your own publically accessible dns server, then dns certbot challenges are great and more flexible than http.
others may suggest neat work arounds for the http challenge issue, but if you have access to a supported dns service I would look at that option. certbot has helpers for quite a few public services as well as support for self hosted dns servers. I run my own public dns servers, so thats the option I chose and use certbot hooks, cron and bash scripts to rsync the updated carts to the propr hosts for the various services I run privately and publicly.
I use letsencrypt a lot, if firewalls are an issue I’ll use dns authentication.
If you are struggling and need a quick fix, the free tier of zero ssl will do a similar thing
I used it to get a cert for my printer
Check your router and see if you’ve forwarded the port to your server.
Sounds like you have nothing listening on port 80 that resolves for your domain for Let’sEncrypt to verify that you own the domain. You need a webserver listening on port 80 and that Certbot can access if you’re using the http method.
Basically you’re forwarding traffic to port 80 but there’s nothing on port 80.
There is another way, I thought. Seem to recall certbot offering it when failing here. If you want more details I can dig into it but it has you create a file in a .well-known and it’ll go check for it there.
Edit: as others mentioned the prerequisite here is that you’re also listening on port 80 somewhere.
Also, don’t forgot let’s encrypt will time you out if you ping too often.
You can use your phone with mobile connection (not WiFi) to check if it can see the file that you made available on your web server.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:
Fewer Letters More Letters DNS Domain Name Service/System HTTP Hypertext Transfer Protocol, the Web IP Internet Protocol TCP Transmission Control Protocol, most often over IP UDP User Datagram Protocol, for real-time communications nginx Popular HTTP server
5 acronyms in this thread; the most compressed thread commented on today has 15 acronyms.
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