Blocked by CORS Policy

[UsgsMonkey]

Greetings,

Just in the last few days, we've run into issues running our Leaflet-based web portal @ https://hydromaintenance.nationalmap.gov/hmp which makes use of BootstrapCdn due to apparent CORS conflicts ...

We are using an older vintage of the library - but this is by necessity since it's a dependency of our Leaflet framework. Here are our existing stylesheet linkages:

<!-- Load Bootstrap 3.3.7: Latest compiled and minified CSS (requires JQuery) -->
<link rel="stylesheet"
      href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"
      integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u"
      crossorigin="anonymous">

<!-- Load Bootstrap 3.3.7: Optional theme (requires JQuery) -->
<link rel="stylesheet"
      href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css"
      integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp"
      crossorigin="anonymous">

<!-- Load Bootstrap 3.3.6: necessary somehow for styles to properly render; may want to reconsider
resetting original Bootstrap version to 3.3.6 -->
<link rel="stylesheet"
      href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css"
      integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7"
      crossorigin="anonymous">

Any assistance would be greatly appreciated!!! This is an important website that we need to keep live to serve our partners.

Regards,

Brett Dev Lead USGS NGTOC

[jimaek]

I have a feeling its not a CORS issue. Can you please try to open the file directly and see what you get? https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css

Do it on the same computer the screenshot came from. Additionally please ping "maxcdn.bootstrapcdn.com" and tell me the IP address you get

[UsgsMonkey]

It looks like I get a 504 error when I try to hit the CSS directly via Chrome. Pinging the address gets me the following...

When I try to reach the address outside the VPN firewall, I can reach it successfully - but that doesn't help our website :P

[UsgsMonkey]

I'm in contact with internal IT. Hopefully this can be resolved with their assistance.

[jimaek]

Can you actually traceroute it? And how does the 504 error look like? Because I think it's a LAN issue on your side, maybe a firewall?

[UsgsMonkey]

I think you're right. Good thought on tracert. I'm forwarding the issue to our IT. Sorry for the trouble and thanks for the assist.