How to see if an IP address belongs inside of a range of IPs using CIDR notation?
c#, cidr, ip
Solution
Decided to answer my own question so people can benefit. If it can be improved, please do!
I used the IPNetwork library and it worked out fantastically!
nuget install IPNetwork2
Below is the code I used:
using System.Net;
public static class RedirectHelpers
{
public static bool IpIsWithinBoliviaRange(string ip)
{
IPAddress incomingIp = IPAddress.Parse(ip);
foreach (var subnet in Bolivia_Ip_Range)
{
IPNetwork network = IPNetwork.Parse(subnet);
if (IPNetwork.Contains(network, incomingIp))
return true;
}
return false;
}
private static List<string> Bolivia_Ip_Range = new List<string>()
{
"12.144.86.0/23",
"31.201.1.176/30",
"46.36.198.101/32",
"46.36.198.102/31",
"46.36.198.104/31",
"46.136.172.0/24",
"63.65.11.0/24",
"63.65.12.0/25",
"63.65.12.128/26",
"63.65.12.192/27",
"63.65.12.224/28",
"63.65.12.240/29",
"63.65.12.248/30",
"63.65.12.252/31",
"63.65.12.254/32",
"65.173.56.0/21",
"67.23.241.179/32",
"67.23.241.180/30",
"67.23.241.184/29",
"67.23.241.192/30",
"67.23.241.196/31",
"67.23.241.198/32",
"72.32.164.56/29",
"72.46.244.32/28",
"74.91.16.48/29",
"74.91.16.208/29",
"74.91.20.48/28",
"74.91.20.64/29",
"74.112.134.120/29",
"74.112.135.104/29",
"74.205.37.16/29",
"78.24.205.32/28",
"98.129.27.88/29",
"98.129.91.40/29",
"166.114.0.0/16",
"167.157.0.0/16",
"174.143.165.80/29",
"186.0.156.0/22",
"186.2.0.0/17",
"186.27.0.0/17",
"190.0.248.0/21",
"190.3.184.0/21",
"166.114.0.0/16",
"167.157.0.0/16",
"186.2.0.0/18",
"190.11.64.0/20",
"190.11.80.0/20",
"190.103.64.0/20",
"190.104.0.0/19",
"190.107.32.0/20",
"190.129.0.0/17",
"190.181.0.0/18",
"190.186.0.0/18",
"190.186.64.0/18",
"190.186.128.0/18",
"200.7.160.0/20",
"200.58.64.0/20",
"200.58.80.0/20",
"200.58.160.0/20",
"200.58.176.0/20",
"200.75.160.0/20",
"200.85.128.0/20",
"200.87.0.0/17",
"200.87.128.0/17",
"200.105.128.0/19",
"200.105.160.0/19",
"200.105.192.0/19",
"200.112.192.0/20",
"200.119.192.0/20",
"200.119.208.0/20",
"201.222.64.0/19",
"201.222.96.0/19"
};
}
Problem
Here I have a static reference the ranges I need to check: ``` private static List<string> Ip_Range = new List<string>() { "12.144.86.0/23", "31.201.1.176/30", "46.36.198.101/32", "46.36.198.102/31", "46.36.198.104/31", "46.136.172.0/24", "63.65.11.0/24", "63.65.12.0/25", "63.65.12.128/26", "63.65.12.192/27", "63.65.12.224/28", "63.65.12.240/29", "63.65.12.248/30", "63.65.12.252/31", "63.65.12.254/32", "65.173.56.0/21", "67.23.241.179/32", "67.23.241.180/30", "67.23.241.184/29", "67.23.241.192/30", "67.23.241.196/31", "67.23.241.198/32", "72.32.164.56/29", "72.46.244.32/28", "74.91.16.48/29", "74.91.16.208/29", "74.91.20.48/28", "74.91.20.64/29", "74.112.134.120/29", "74.112.135.104/29", "74.205.37.16/29", "78.24.205.32/28", "98.129.27.88/29", "98.129.91.40/29", "166.114.0.0/16", "167.157.0.0/16", "174.143.165.80/29", "186.0.156.0/22", "186.2.0.0/17", "186.27.0.0/17", "190.0.248.0/21", "190.3.184.0/21" }; ``` Here's some pseudo code on how I see it working: ``` public static bool IpIsWithinRange(string ip) //Something like 127.0.0.1 or 184.56.26.35 { IPAddress incomingIp = IPAddress.Parse(ip); foreach (var subnet in Ip_Range) { IPAddress sub = IPAddress.Parse(subnet); ????? if (incomingIp "is in" sub) ? return true; } return false; } ``` Any suggestions on how to code up this functionality?