In a previous post, I demonstrated a Korn shell script which determined the subnet mask for a range of IPv4 addresses. Perl has a module called Net::IP which provides a number of functions which can be used to manipulate IPv4 (and also IPv6) addresses to provide the same information and a lot more besides.
For example, the following code outputs a lot of information about a classless prefix:
use Net::IP;
my $ip = new Net::IP ('10.1.1.0/24') or die (Net::IP::Error());
print ("IP : ".$ip->ip()."n");
print ("Sho : ".$ip->short()."n");
print ("Bin : ".$ip->binip()."n");
print ("Int : ".$ip->intip()."n");
print ("Mask: ".$ip->mask()."n");
print ("Last: ".$ip->last_ip()."n");
print ("Len : ".$ip->prefixlen()."n");
print ("Size: ".$ip->size()."n");
print ("Type: ".$ip->iptype()."n");
print ("Rev: ".$ip->reverse_ip()."n");
gives
Mask: 255.255.255.128 Prefix: 10.1.1.0/25 IP : 10.1.1.0 Sho : 10.1.1 Bin : 00001010000000010000000100000000 Int : 167837952 Mask: 255.255.255.0 Last: 10.1.1.255 Len : 24 Size: 256 Type: PRIVATE Rev: 1.1.10.in-addr.arpa.
The following example determines the subnet prefix for a range of addresses:
my $ip = new Net::IP('10.1.1.0-10.1.1.127') or die(Net::IP::Error());
print("Mask: ".$ip->mask()."n");
print("Prefix: ".$ip->prefix()."n");
gives
Mask: 255.255.255.128 Prefix: 10.1.1.0/25
hi,
I have a subnet and subnet length. like 192.168.1.0 length 8. how do I convert this in CIDR form like 192.168.1.0/29 ?
is there is straight way function for this ?
Regards,
-Manish