Address in subnet check
Paste the addresses you are looking for and the blocks you hold. For each address, see every block that contains it, with the most specific one first, and spot addresses that are not in any of your blocks.
Runs in your browser. Nothing you enter or upload is sent to us.
How to use it
Three steps
- List the addresses. One per line, IPv4 or IPv6. You can also enter blocks to check whether a whole block sits inside yours.
- List your blocks. Paste your pools, customer blocks or routes, one per line.
- Read the matches. The most specific block is shown first, which is the one a router would use.
Questions
Good to know
What does most specific mean?
The matching block with the longest prefix. If 203.0.113.70 is inside both 203.0.113.0/24 and 203.0.113.64/29, the /29 is the most specific match.
Can I check a block instead of an address?
Yes. Enter a block such as 203.0.113.64/28 and it matches only blocks that contain all of it.
How many can I check at once?
Up to 5,000 addresses against 20,000 blocks, all in your browser.
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Still tracking IPs in a spreadsheet?
IPAM Enterprise keeps every /24, block, customer and circuit in one portal, and checks each assignment for overlaps before it is saved.