32-bit unsigned integers are IPv4 addresses. Meanwhile, the IPAddress.Address property, while deprecated, is an Int64 that returns the unsigned 32-bit value of the IPv4 address (the catch is, it’s in network byte order, so you need to swap it around). For example, my local google.com is at 64.233.187.99. That’s equivalent to: 64*2^24 + 233*2^16 + … Read more
It is true that a typical IPv4 header is 20 bytes, and the UDP header is 8 bytes. However it is possible to include IP options which can increase the size of the IP header to as much as 60 bytes. In addition, sometimes it is necessary for intermediate nodes to encapsulate datagrams inside of … Read more
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 (\.|$) is only required if the number is less than 200. ‘\b((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4}\b’ ^ ^