# IP whitelisting

IP whitelisting authenticates proxy connections by their source IP address: the customer registers the public addresses of its machines, and the gateway accepts connections from them without a username or password. It removes secrets from configuration and suits fixed servers, but it fails when the source address changes and it does not work from networks whose public IP is shared with strangers.


## When it fits

- Servers and VPS with a static public IPv4.
- Tools that cannot hold credentials: browser proxy flags, some anti-detect profiles, appliances.
- Environments where a leaked password would be worse than a leaked address.


## When it does not

- Laptops on home or mobile connections, containers with changing egress, serverless functions.
- Shared egress (offices, universities, CGNAT): anyone behind the same address would be authenticated as you.
- IPv6-only hosts, when the provider whitelists IPv4 only.


## Targeting still works

On rotating pools the username carries the location and session parameters. With a whitelisted address you still send a username (any password) so the gateway can read them.


## How it works at ProxShift

ProxShift whitelists up to 50 IPv4 addresses per account, applied within a minute, from the dashboard or POST /v1/whitelist; whitelisted connections carry parameters in the username and any password.

Source: https://proxshift.com/glossary/ip-whitelisting