Php is used to obtain the start and end IP addresses of a CIDR block.

Php is used to obtain the start and end IP addresses of a CIDR block.

This example describes how to obtain the start and end IP addresses of a network segment in php. Share it with you for your reference. The details are as follows:

For example, for a network segment (192168.1.5/24), its subnet mask is divided:
11111111.11111111.11111111.00000000 (255.255.255.0)
Note: If the IP address is 32 bits, 24 indicates that there are 24 first 1 and 8 are later 0 in the network segment division.
The algorithm for starting an IP address is: the binary of 192.168.1.5 and the binary of the subnet mask.
The algorithm for ending an IP address is: The subnet mask is first reversed, and then "or" is performed with the 192.168.1.5 binary.
In practice, the network address and broadcast address are obtained as follows. network address + 1 is the first host address, and broadcast address-1 is the last host address.

<? Phpfunction mask2bin ($ n) {$ n = intval ($ n); if ($ n <0 | $ n> 32) die ('error submask '); return str_repeat ("1", $ n ). str_repeat ("0", 32-$ n);} function revBin ($ s) {$ p = array ('0', '1', '2 '); $ r = array ('2', '0', '1'); return str_replace ($ p, $ r, $ s);} function startIp ($ str, $ bSub) {$ bIp = decbin ($ str); $ bIp = str_pad ($ bIp, 8, "0", STR_PAD_LEFT ); $ sIp = bindec ($ bIp & $ bSub); return $ sIp;} function endIp ($ str, $ bSub) {$ bIp = decb In ($ str); $ bIp = str_pad ($ bIp, 8, "0", STR_PAD_LEFT); $ eIp = bindec ($ bIp | revBin ($ bSub )); return $ eIp;} $ ip = array ('20160301', '20160301', '1', '5'); // you can obtain the ip address from the form, here we will only demonstrate $ mask = '24'; // set the mask $ bSub = mask2bin ($ mask); // convert the subnet mask to binary $ mask = array (); $ mask [] = substr ($ bSub, "0", 8); // divide the subnet mask into segments every 8 bits $ mask [] = substr ($ bSub, "8", 8); $ mask [] = substr ($ bSub, "16", 8); $ mask [] = substr ($ bSub, "24 ", 8); echo '<table summary = "result" bord Er = "1" cellspacing = "1" cellpadding = "0"> <tbody> <td align = "right"> <font size = "2"> mask: </font> </td> <font size = "2"> '; for ($ I = 0; $ I <4; $ I ++) {echo bindec ($ mask [$ I]); if ($ I! = 3) echo ". ";} echo '</font> </td> </tr> <td align =" right "> <font size =" 2 "> network address: </font> </td> <font size = "2"> '; for ($ I = 0; $ I <4; $ I ++) {echo startIp ($ ip [$ I], $ mask [$ I]); if ($ I! = 3) echo ". ";} echo '</font> </td> </tr> <td align = "right"> <font size = "2"> first available: </font> </td> <font size = "2"> '; for ($ I = 0; $ I <3; $ I ++) {echo startIp ($ ip [$ I], $ mask [$ I]); echo ". ";}$ ip_4 = startIp ($ ip [3], $ mask [3]); echo ++ $ ip_4; echo '</font> </td> </tr> <td align = "right"> <font size = "2"> available at last: </font> </td> <font size = "2"> '; for ($ I = 0; $ I <3; $ I ++) {echo endIp ($ ip [$ I], $ mask [$ I]); echo ". ";}$ ip_4 = endIp ($ ip [3], $ mask [3]); echo -- $ ip_4; echo '</font> </td> </tr> <td align = "right"> <font size = "2"> broadcast address: </font> </td> <font size = "2"> '; for ($ I = 0; $ I <4; $ I ++) {echo endIp ($ ip [$ I], $ mask [$ I]); if ($ I! = 3) echo "." ;}?>

I hope this article will help you with php programming.