# Change CIDR Block

## Prerequisites

* The instance is **Running**.

## Procedures

1. Click the IP Transit name and go to **Information** > **CIDR block** > **Add CIDR Block**.

   <figure><img src="/files/GCYVvrPIzxCLYNHn29Ez" alt=""><figcaption></figcaption></figure>
2. Select the IP type and block size, review the price, and confirm.

   <div align="left"><figure><img src="/files/uo1Kp1KC20VvMj69PDhY" alt="" width="302"><figcaption></figcaption></figure></div>

## Result

The new CIDR block appears in the list.

{% hint style="info" %} <mark style="color:blue;">**Note**</mark>

* <mark style="color:blue;">You need at least one public CIDR block. You can only delete a CIDR block if at least two are configured.</mark>
* <mark style="color:blue;">You cannot perform operations while IP Transit is Processing.</mark>
  {% endhint %}


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