Can't access from ColoCrossing


Hello, my server ip seems blocked by, my server ip is

when ping from, I got response “PING ( 56(84) bytes of data.” then wait forever there after.

Please help this, thanks

Customer support


@lestaff can someone please spilt this and previous reply out?

Ping could never determine if your IP is being blocked by let’s encrypt…
Please try to curl let’s encrypt and see the output.

Thank you


Hi. I split this into a new topic.

I’m always uncomfortable coming up with titles for other people’s posts. :worried:

Let’s Encrypt doesn’t block clients that way. I don’t think the CDN does, at least under normal circumstances.

I don’t have trouble using that edge IP from a different ISP in the region. :confused: (My resolver gives me a different PoP, though.)

What does, say, “mtr -brwz” show?

Are you able to access other things using Akamai’s CDN?


Hi @gamingtips

there is as domain name. Is this your domain? If yes, the staging system of letsencrypt is able to connect your domain:


Yes, is my domain. I use vesta panel, I ried to get SSL certificate of from letsencrypt but failed.

ping / from server failedm seems server ip blocked by /

from , you can see the problem too under “LetsEncryptStaging” section


No, this is not the problem. Let’s debug isn’t able to put a file on your webserver.

Let’s debug checks, if there is a 404 instead of a timeout, connection refused or something else (DNS-error).

Let’s debug creates an order, but isn’t able to change your webserver. That’s good :wink:



Ping doesn’t represent anything (since some server, like mine, rejects ping request)

Please try to connect via curl…

curl -I

If this is not working for you… please reply.

Thank you


Just tried curl -I

After waiting for long, got this error message “curl: (7) couldn’t connect to host”



emm… That’s wierd…

Could you also check this command?
curl -I -v

Thank you


Same, can’t connect. Is it possible my server ip blocked by your end firewall ?


My server only have IPV4 no IPV6 , will that casue problem?


I don’t think let’s Encrypt is blocking your IP…

That would not cause this issue…

Just to confirm… Could you please try this command?
curl -I -v ( is using akamai too… So I guess if your IP is being blocked, you might not be able to access either)

Please also try curl -I -4

Thank you


[root@busymart ~]# curl -I -v

  • About to connect() to port 443 (#0)
  • Trying… Connection timed out
  • Trying 2600:141b:13:289::3a8e… Connection timed out
  • Trying 2600:141b:13:29a::3a8e… Connection timed out
  • couldn’t connect to host
  • Closing connection #0
    curl: (7) couldn’t connect to host


tried, it is good, can connect and get response

but curl -I -4 failed, can’t connect to



In this case, I could suggest to find a let’s encrypt staff to help you(and Ive pinged them)… @lestaff can someone please take a look at his issue?

Thank you


Thanks, really appreciate


Hi @gamingtips,

Could you provide some more debugging information for us to provide Akamai? If you could run the following commands from the affected server and share the output from each it would be very helpful:

curl ; echo
curl ; echo
dig +short TXT
dig +short TXT
dig +short TXT
dig +short TXT
dig +short TXT
mtr -c 20 -w -r

You may need to install a package to get the mtr command (I believe its mtr-tiny on Ubuntu/debian systems)


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