compare two ip with C#
Solution 1
It seems System.Net.IPAddress defines it's own Equals override so this should work:
IPAddress ip1 = IPAddress.Parse("123.123.123.123");
IPAddress ip2 = IPAddress.Parse("124.124.124.124");
if(ip1.Equals(ip2))
{
//...
}
Solution 2
The type IPAddress
in the BCL supports equality and can be used for this purpose.
public static bool IsSameIPAddress(string ip1, string ip2) {
IPAddress leftIP = IPAddress.Parse(ip1);
IPAddress rightIP = IPAddress.Parse(ip2);
return leftIP.Equals(rightIP);
}
Several people have wondered why a straight string comparison is not sufficient. The reason why is that an IP address can be legally represented in both base 10 and hexidecimal notation. So the same IP address can have more than 1 string representation.
For example
var left = "0x5.0x5.0x5.0x5";
var right = "5.5.5.5";
IsSameIPAddress(left,right); // true
left == right; // false
Solution 3
Check out Equals method on System.Net.IPAddress
Solution 4
The IPAddress
class (System.Net) has an overridden Equals method that will compare the addresses, not the object instances, which is what you want. String comparison here may be dangerous since it is possible for IP addresses to have more than one string representation.
http://msdn.microsoft.com/en-us/library/system.net.ipaddress.equals%28v=VS.71%29.aspx
IPAddress.Parse(ip1).Equals(IPAddress.Parse(ip2))
Solution 5
IPAddress addr1 = IPAddress.Parse(ip1);
IPAddress addr2 = IPAddress.Parse(ip2);
return (addr1.Equals(addr2));
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user319854
Updated on December 12, 2020Comments
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user319854 about 3 years
How I can compare two IP address?
string ip1 = "123.123.123.123"; string ip2 = "124.124.124.124";
I need some like this:
if(ip1 == ip2) { //true }
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Luis over 13 yearsHow come the code you just posted dont suit your needs?
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JaredPar over 13 years@Luis, because the same IP address can have a different string representation since the numbers can legally be represented in both hex and base 10 notation.
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R. Martinho Fernandes over 13 years@Luis: Try this:
ping 2130706433
.
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KMån over 13 years@JaredPar:
leftIP==rightIP
in your first code would return false for same IP address! It should bereturn LeftIP.Equals(rightIP);
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JaredPar over 13 years@KMan, just noticed that myself and updated my post. Thanks for pointing it out!
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Rich over 13 yearsThe hex stuff was new to me. Interesting. It also gets worse with IPv6, since you don't have to shorten the addresses with
::
there. -
Powerlord over 13 yearsI've never seen dotted hex format used. non-dotted hex yes (0x05050505), but never dotted hex.
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JaredPar over 13 years@OMG Unicorns, both forms are legal at least in respect to what
IPAddress.Parse
supports. I'm not sure about the official IP standard off the top of my head though. -
Lee over 6 years@PhucNguyen -
IPAddress.Parse("172.16.0.150").Equals(IPAddress.Parse("172.16.1.216"))
returns false for me as expected.