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dropkickjunk
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dropkickjunk

Firewall: External Content Blocked

August 6, 2013 5.5k views
I followed the firewall guide here: https://www.digitalocean.com/community/articles/how-to-setup-a-basic-ip-tables-configuration-on-centos-6 However, I'm not able to view images from other websites and recaptcha cannot connect to validate captcha input. http://www.google.com/recaptcha/api/verify
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15 Answers
kamaln7 MOD August 6, 2013
> However, I'm not able to view images from other websites and recaptcha cannot connect to validate captcha input.

Are they on a website and you cannot access them? I'm not sure what you mean -- please elaborate
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dropkickjunk August 6, 2013
External images, so hosted on other websites, in img src tags on my website.

The recaptcha url sends a request for validation and gets a response back as to whether it matches.
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kamaln7 MOD August 6, 2013
The IPTables rules should not affect that. The problem is on your end - try accessing your website from another computer/network/browser. Are you mixing http/https content?
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dropkickjunk August 6, 2013
I figured it was some kind of blocked port that stopped traffic from external sources reaching my site.

My website is accessible by all.

No there is no https content.
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kamaln7 MOD August 6, 2013
Try deleting all of your iptables rules (as root): 

iptables-save > ~/iptables_backup && iptables -F


If that doesn't fix it, iptables isn't what's causing the issue.
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dropkickjunk August 6, 2013
I get permission denied on that statement even when I sudo
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kamaln7 MOD August 6, 2013
Run this command then: 

sudo su -c "iptables-save > ~/iptables_backup && iptables -F" root
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dropkickjunk August 6, 2013
I did

sudo service iptables stop

and the issue remains, is that the same thing as you suggested trying?
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dropkickjunk August 6, 2013
the issue of not being able to load the images*

the command worked fine
iptables: Flushing firewall rules: [ OK ]
iptables: Setting chains to policy ACCEPT: filter [ OK ]
iptables: Unloading modules: [ OK ]
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dropkickjunk August 6, 2013
Is a recaptcha-not-reachable error from the ReCaptcha.pm perl module. I've tried a number of verify URLs including

http://www.google.com/recaptcha/api/verify
http://api-verify.recaptcha.net
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dropkickjunk August 6, 2013
Recaptcha and external images used to work fine on my old shared hosting, so it must be some configuration issue?
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kamaln7 MOD August 6, 2013
It must be a configuration issue. Disabling iptables didn't fix it therefore the firewall isn't blocking it :]
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dropkickjunk August 6, 2013
This is how I'm trying to get the images (Perl)

my $img = LWP::UserAgent->new->request(new HTTP::Request GET => $url);

$img->is_success is always false

This used to work fine on my old server so I'm not sure what's going on, any ideas?
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dropkickjunk August 6, 2013
dodgy perl module, fixed image issue now, thanks :)
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kamaln7 MOD August 6, 2013
Awesome, glad to hear that! :]
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