These are dynamically configured link-local addresses. They are only valid on a single network segment and are not to be routed. Of particular note, 169.254.169.254 is used in AWS, Azure and other cloud computing platforms to host instance metadata service.
The whole idea behind the MX record is to specify a host or hosts which can accept mail for a domain. As specified in RFC 1035, the MX record contains a domain name. It must therefore point to a host which itself can be resolved in the DNS. An IP address could not be used … Read more
It’s very bad. Here is a list of examples of what I have first hand experience with consumer ISPs doing to fight the shortage of IPv4 addresses: Repeatedly shuffling around IPv4 blocks between cities causing brief outages and connection resets for customers. Shortening DHCP lease times from days to minutes. Allow users to choose if … Read more
The only thing is that you’re not saying “all addresses should have access” — that’s done in your firewall(s) and/or the server software and/or other security layers like tcpwrappers. 0.0.0.0, in this context, means “all IP addresses on the local machine” (in fact probably, “all IPv4 addresses on the local machine”). So, if your webserver … Read more
Unfortunately the standard DNS A-record (domain name to IP address) used by web-browsers to locate web-servers does not include a port number. Web-browsers use the URL protocol prefix (http://) to determine the port number (http = 80, https = 443, ftp = 21, etc.) unless the port number is specifically typed in the URL (for … Read more
output looks like below
I would use a web service that can return JSON (along with jQuery to make things simpler). Below are all the active free IP lookup services I could find and the information they return. If you know of others, then please add a comment and I’ll update this answer. Abstract Run code snippetExpand snippet Limitations: 10,000 requests … Read more
This won’t work always (returns 127.0.0.1 on machines having the hostname in /etc/hosts as 127.0.0.1), a paliative would be what gimel shows, use socket.getfqdn() instead. Of course your machine needs a resolvable hostname.
You’ve already got a working answer but just in case you are curious what was wrong with your original approach, the answer is that you need parentheses around your alternation otherwise the (\.|$) is only required if the number is less than 200.
Whatever you do, make sure not to trust data sent from the client. $_SERVER[‘REMOTE_ADDR’] contains the real IP address of the connecting party. That is the most reliable value you can find. However, they can be behind a proxy server in which case the proxy may have set the $_SERVER[‘HTTP_X_FORWARDED_FOR’], but this value is easily spoofed. For example, … Read more