Let\u2019s say you are running a poor man\u2019s website where you are just testing stuff but have no real intention of buying a domain name or paying your ISP to give you a static IP address.<\/p>\n\n\n\n
If you want to access your test site remotely, you need to know your public IP address, however your home ISP gives you a dynamic public IP address and every time you have a power failure, or reboot your router, you are assigned a brand new public IP address. This makes it very annoying if you are testing your site remotely.<\/p>\n\n\n\n
Sure, you could use a Dynamic DNS service to keep track of when your public IP address changes, but what if you have a paranoid client who does not want to use even Dynamic DNS? How do you keep track of your new public IP without having to get to your internal network to read it each time?<\/p>\n\n\n\n
What you need is a way to be able to have the system send you an email with your current public IP address so that there is no guess work involved. But how do we do this?<\/p>\n\n\n\n
To determine your public IP, you need to have an external site to refer to which will record your public IP as connecting to it. You could use services such as What Is My IP or similar, but we don\u2019t want to rely on an external service<\/em>, nor do we want to hammer a third-party service with requests. Basically we just want to replicate the functionality of such a site as locally as possible and then use an email tool to send the information to you in a message.<\/p>\n\n\n\n Pre-requisites:<\/p>\n\n\n\n Now let\u2019s look at using a simple bit of PHP to obtain the address of the connecting host.<\/p>\n\n\n\n NOTE: Some ISP\u2019s do not allow connections on dynamic IP\u2019s to send periodic email on their mail server and may block it on the belief that your emails may be spam. Should that be the case, you should install a local mail daemon such as Postfix and change the sendemail arguments to direct their mail to localhost<\/em> instead, and allow Postfix to send the notification email. In Ubuntu, you can install Postfix by simply installing the postfix<\/em> package and electing the server to be an \u201cInternet Site\u201d. The default configuration is fine, but not secure. Ensure that no-one externally can access port 25 on your client\u2019s server if you choose to go down this route.<\/p>\n","protected":false},"excerpt":{"rendered":" Let\u2019s say you are running a poor man\u2019s website where you are just testing stuff but have no real intention of buying a domain name or paying your ISP to give you a static IP address. If you want to access your test site remotely, you need to know your public IP address, however your […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-43","post","type-post","status-publish","format-standard","hentry","category-tutorials"],"_links":{"self":[{"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/posts\/43","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/comments?post=43"}],"version-history":[{"count":1,"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/posts\/43\/revisions"}],"predecessor-version":[{"id":44,"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/posts\/43\/revisions\/44"}],"wp:attachment":[{"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/media?parent=43"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/categories?post=43"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.serenux.com\/index.php\/wp-json\/wp\/v2\/tags?post=43"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/li><?php
$ip = getenv(\"REMOTE_ADDR\");
echo $ip;
?><\/code>
<\/li>
<\/li>
<\/li>
If you ran this PHP locally, you would get the internal IP of the connecting host instead, eg:\u00a0192.168.0.100<\/em>\u00a0or similar instead.
<\/li>$ sudo apt-get install sendemail<\/code>
<\/li>$ nano \/home\/noddy\/getpublicip.sh<\/code>
<\/li>#!\/bin\/bash
wget -O- http:\/\/www.myisp.com\/~noddy\/getmypublicip.php 2>\/dev\/null | sendemail -u \"Client's public IP address\" -f test@blah.com -t noddy@mycompany.com -s mail.mycompany.com<\/code>
<\/li>
<\/li>$ sh \/home\/noddy\/getpublicip.sh<\/code>
<\/li>
<\/li>$ crontab -e<\/code>
<\/li>0 * * * * sh \/home\/noddy\/getpublicip.sh<\/code>
<\/li>
<\/li>
<\/li>*\/15<\/strong> * * * * sh \/home\/noddy\/getpublicip.sh<\/code>
<\/li>