(6) Couldn't resolve host 'api-3t.paypal.com'

Hello, the last 6-7 days i have had troubleto use paypal express on my site.

I use Zen cart v1.5 with paypal express.
My host is host1.no and my url is https://www.elektroarena.net and https://www.makeupheaven.no
I have the same problem on both sites..

But sometimes the payment goes through. I get the error about 2 out of 10 times.

The error code is : (6) Couldn't resolve host 'api-3t.paypal.com'

I have talked to my host and they say that they can resolve api-3t.paypal.com at the same time as i get the error in my cart. So they say that there is no problem at the server.

What could be wrong?

The host i located in Norway, i use LIVE api server, and api signature.

I have a script called ipncheck.php where i get this error:
CURL ERROR: Attempted connection on: https://www.paypal.com/cgi-bin/webscr

(6) Couldn't resolve host 'www.paypal.com'

Trying direct HTTP on port 80 instead ...

CURL RESPONSE RECEIVED - Communications OKAY
IPN TESTING - Response Received via CURL -- COMMUNICATIONS OKAY

IPN TESTING - Confirmation/Validation response with fsockopen(): FSOCKOPEN() RESPONSE RECEIVED - Communications OKAY

Default method likely to be used for communications is: CURL, with the fallback method being FSOCKOPEN if possible.

Script finished.

And sometimes i get no error with the script.

elektroarena:

But sometimes the payment goes through. I get the error about 2 out of 10 times.

The error code is : (6) Couldn't resolve host 'api-3t.paypal.com'

I have talked to my host and they say that they can resolve api-3t.paypal.com at the same time as i get the error in my cart. So they say that there is no problem at the server.

What could be wrong?

Forget what your host has told you. The problem is with your/their nameserver(s). The intermittent nature of the problem indicates that all is set up correctly, but for reasons I can't identify it isn't getting a response in a timely manner. This is almost always caused by one of 3 possible things.

1. Your server is being overloaded
2. The network between your server and the DNS servers are being swamped
3. The DNS server(s) are being overloaded.

I've checked/verified the problem on your site and there is no evidence that it is your server being overloaded, which means a network or DNS problem. Neither is something that you can fix. It is something your host needs to take care of.

The fact that your host can resolve this address whilst your server cannot is easily explained by the fact that they are using 4 nameservers (which is good) and thier lookups are/were using a different server than your server.

There ARE ways that you can eliminate this problem by editing the zencart/paypal code to use one of PayPals IP addresses rather than hostname, but it's not good practice and will eventually cause problems of its own. Nonetherless it is an effective way to mitigate DNS lookup issues (and it will provide evidence to your host that it is a nameserver issue rather than a zencart store issue.

Having said that, if DrByte or any of the zencart team provide different advice than this take their advice over mine. They have a lot more experience with PayPal issues than I do. Besides, a second opinion never goes astray. :)

Cheers
Rod

RodG:

The problem is with your/their nameserver(s).

...

It is something your host needs to take care of.Agreed.
RodG:

There ARE ways that you can eliminate this problem by editing the zencart/paypal code to use one of PayPals IP addresses rather than hostname, but it's not good practice and will eventually cause problems of its own.
Agreed again.
Using a direct IP address as a SHORT and TEMPORARY test is suitable for testing only. Do NOT rely on it as a long-term solution. PayPal does change their server addresses from time to time, and hard-coding the IP address will cause you more trouble in the end. It is not a proper fix.

Get your host to fix their server configuration problem.

Perhaps their /etc/resolv.conf file is damaged or is pointing to destinations which are no longer working as expected. Again, that's something that only the server's primary administrator can fix.

Thank you very much for two very good answers!
I will get back to my host and ask whats going on.