Hi, I'm looking for any tool or a way I could specify a CIDR and the prefixes that are being used within this CIDR and the tool show me all free supernets. Example: 192.168.0.0/24 - CIDR Used subnet's: 192.168.0.1/32 192.168.0.8/27 192.168.0.64/26 192.168.0.68/32 192.168.0.96/29 Tool Result => Free Subnet's: 192.168.0.2/31 192.168.0.4/30 192.168.0.32/27 192.168.0.128/25 Regards, John
most reasonable ipam tools will track or express unallocated vs allocated space. netdot has a lovely address-space container/block view for managing free vs allocated space joel On 10/31/15 9:51 AM, John Steve Nash wrote:
Hi,
I'm looking for any tool or a way I could specify a CIDR and the prefixes that are being used within this CIDR and the tool show me all free supernets.
Example:
192.168.0.0/24 - CIDR
Used subnet's:
192.168.0.1/32 192.168.0.8/27 192.168.0.64/26 192.168.0.68/32 192.168.0.96/29
Tool Result => Free Subnet's:
192.168.0.2/31 192.168.0.4/30 192.168.0.32/27 192.168.0.128/25
Regards,
John
On Oct 30, 2015, at 7:51 PM, John Steve Nash <john.steve.nash@gmail.com> wrote:
Hi,
I'm looking for any tool or a way I could specify a CIDR and the prefixes that are being used within this CIDR and the tool show me all free supernets. <snip>
I've used subnetsmngr for this in the past. Proper usage of it thru the UI forces you to fully allocate (as compared to sparse allocating) your subnets, basically the same way subetting is taught in base level networking certifications. This makes finding the un-used subnets very easy. http://sourceforge.net/p/subnetsmngr/wiki/Home/ <http://sourceforge.net/p/subnetsmngr/wiki/Home/> NIPAP allows you to do the same as well, but will let subnets be sparse allocated, so you won't necessarily have pre-created them waiting to be used later on. http://spritelink.github.io/NIPAP/ <http://spritelink.github.io/NIPAP/> NIPAP also has a nice CLI interface. Both are also open source, full v4/v6. Theo
Attached is a perl script I wrote for a coworker that you can tweak as you'd like. It's designed to log into a router and dump the route table(s) and find used/unused subnets in a given supernet. Available routes are green and used routes are red. Yellow routes are routes where we have route and a more specific route so the first route is probably an aggregate and there _may_ be open space available. On Fri, Oct 30, 2015 at 8:51 PM, John Steve Nash <john.steve.nash@gmail.com> wrote:
Hi,
I'm looking for any tool or a way I could specify a CIDR and the prefixes that are being used within this CIDR and the tool show me all free supernets.
Example:
192.168.0.0/24 - CIDR
Used subnet's:
192.168.0.1/32 192.168.0.8/27 192.168.0.64/26 192.168.0.68/32 192.168.0.96/29
Tool Result => Free Subnet's:
192.168.0.2/31 192.168.0.4/30 192.168.0.32/27 192.168.0.128/25
Regards,
John
Learned that attachments do make it to the list. Here's a link: http://pastebin.com/tMdcfvji On Sat, Oct 31, 2015 at 10:29 AM, inetjunkmail <inetjunkmail@gmail.com> wrote:
Attached is a perl script I wrote for a coworker that you can tweak as you'd like. It's designed to log into a router and dump the route table(s) and find used/unused subnets in a given supernet. Available routes are green and used routes are red. Yellow routes are routes where we have route and a more specific route so the first route is probably an aggregate and there _may_ be open space available.
On Fri, Oct 30, 2015 at 8:51 PM, John Steve Nash < john.steve.nash@gmail.com> wrote:
Hi,
I'm looking for any tool or a way I could specify a CIDR and the prefixes that are being used within this CIDR and the tool show me all free supernets.
Example:
192.168.0.0/24 - CIDR
Used subnet's:
192.168.0.1/32 192.168.0.8/27 192.168.0.64/26 192.168.0.68/32 192.168.0.96/29
Tool Result => Free Subnet's:
192.168.0.2/31 192.168.0.4/30 192.168.0.32/27 192.168.0.128/25
Regards,
John
John, Without going through the hassle of installing a full-blown IPAM solution you could use Python's netaddr library to accomplish what you are asking:
from netaddr import * cidr = IPSet(['192.168.0.0/24']) used = IPSet(['192.168.0.1','192.168.0.8/29','192.168.0.64/26']) cidr ^ used IPSet(['192.168.0.0/32', '192.168.0.2/31', '192.168.0.4/30', '192.168.0.16/28', '192.168.0.32/27', '192.168.0.128/25'])
Jeremiah Millay Senior Network Engineer Vermont Telephone Co., Inc. 354 River Street Springfield, VT 05156
On 31 October 2015 at 01:51, John Steve Nash <john.steve.nash@gmail.com> wrote:
I'm looking for any tool or a way I could specify a CIDR and the prefixes that are being used within this CIDR and the tool show me all free supernets.
For the weekend exercise I wrote a small script that does this. You can find it at http://pastebin.com/i0D54Lsq Usage: cat input.txt | ./subnet.sh The input.txt file contains your input such as: Baldurs-MBP-2:~ baldur$ cat /tmp/x add 192.168.0.0/24 remove 192.168.0.1/32 remove 192.168.0.8/27 remove 192.168.0.64/26 remove 192.168.0.68/32 remove 192.168.0.96/29 Baldurs-MBP-2:~ baldur$ cat /tmp/x | ./subnet.sh 192.168.0.32/27 192.168.0.128/25 Note this was not your expected output, but that is because your example is defective. To get your expected output we can modify the input such as: Baldurs-MBP-2:~ baldur$ cat /tmp/x add 192.168.0.0/24 remove 192.168.0.0/31 remove 192.168.0.3/32 remove 192.168.0.8/29 remove 192.168.0.16/28 remove 192.168.0.64/26 remove 192.168.0.68/32 remove 192.168.0.96/29 Baldurs-MBP-2:~ baldur$ cat /tmp/x | ./subnet.sh 192.168.0.2/32 192.168.0.4/30 192.168.0.32/27 192.168.0.128/25 You can have multiple add lines and add/remove lines in any order. Regards, Baldur
The results appear to be missing 192.168.0.0/32. Is this intended behavior? 192.168.0.8/27 is not a valid CIDR — It actually represents an address within 192.168.0.0/27, so actually, rather than missing 192.168.0.0/32, one could argue that there are erroneous reports for 192.168.0.2/31, 192.168.0.4/30 being available. 192.168.0.64/26 encompasses 192.168.0.68/32 and 192.168.0.96/29, so there’s also an allocation conflict potential there. I thought I understood what you were looking for from your question, but your example creates significant confusion. Owen
On Oct 30, 2015, at 8:51 PM, John Steve Nash <john.steve.nash@gmail.com> wrote:
Hi,
I'm looking for any tool or a way I could specify a CIDR and the prefixes that are being used within this CIDR and the tool show me all free supernets.
Example:
192.168.0.0/24 - CIDR
Used subnet's:
192.168.0.1/32 192.168.0.8/27 192.168.0.64/26 192.168.0.68/32 192.168.0.96/29
Tool Result => Free Subnet's:
192.168.0.2/31 192.168.0.4/30 192.168.0.32/27 192.168.0.128/25
Regards,
John
participants (7)
-
Baldur Norddahl -
inetjunkmail -
Jeremiah Millay -
joel jaeggli -
John Steve Nash -
Owen DeLong -
Theodore Baschak