Generating Let's Encrypt Certificates: Unable to obtain ACME certificate for domains \ Timeout during read (your server may be slow or overloaded)
I'm using [Traefik](https://traefik.io/traefik) in my server which has built-in feature of generating Let's Encrypt certificates for my domains. However, when I deploy my traefik stack, I get this error: ``` Unable to obtain ACME certificate for domains \"domain.com, www.domain.com\": unable to generate a certificate for the domains [domain.com www.domain.com]: error: one or more domains had a problem:\n[domain.com] acme: error: 400 :: urn:ietf:params:acme:error:connection :: Timeout during read (your server may be slow or overloaded), url: \n" providerName=le.acme routerName=stag-domain-com-proxy-https@docker rule="Host(`domain.com`) || Host(`www.domain.com`)" ``` Some observations: - I have other domains in my stack and traefik was able to generate certificates for those. (e.g. it was able to create certificates for sub1.domain.com, sub2.domain.com) - I can ping my ipv4 address, domain.com, www.domain.com and also the ipv6 address using this [tool](https://tools.keycdn.com/ipv6-ping) - It was suggested in the [Traefik forum](https://community.containo.us/t/traefik-not-getting-ssl-certificates-for-some-domains/868/5) to check... > that you can curl on both IPv4 and IPv6 the ip mentioned in the A and AAAA records for the faulty domains? When I run `curl my.ipv4.addr.ess` -- I get a `404 page not found` and when I `curl my:ip::v:6:add:ress` I get `curl: (3) IPv6 numerical address used in URL without brackets` --- What could be causing this issue with generating certificates?