Overlap in CIDR

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#376 1 comment 0 reactions 1 assignee View on GitHub

@DCMattyG is already working on this.

Since Feb 27, 2026.

Assessment

This issue has not been assessed yet.

Description

bug

Describe the bug
There are some vnet's which got created with overlap CIDR ranges, and we can see both CIDRs are makred as associated as well.
To Reproduce
Steps to reproduce the behavior:
Not sure how to reproduce this as this is not permanent issue

Expected behavior
CIDRs shouldn't be overlapped atleast once those are associated to an existing vnets. Reservations shouldn;t evn provide those ranges

Screenshots

Image

⚠️ Found 5 overlap(s): just adding one here for security reason

OVERLAP DETECTED:
VNet 1: ***
Address Spaces: 10.43.2.192/26

VNet 2: ***
Address Spaces: 10.43.2.192/28

Overlapping CIDRs:
- 10.43.2.192/26 <-> 10.43.2.192/28

Additional context
We have observed this behaviour for few vnets as mentioned above.

Dominant language
JavaScript
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