463 X-Forwarded-For Too Many IPs (ALB)

AWS ALB: the request's X-Forwarded-For header contained more than 30 IP addresses.

463 at a glance

Code: 463
Name: X-Forwarded-For Too Many IPs (ALB)
Class: 4xx Client error
Status: Non-standard used by AWS Application Load Balancer
Documented by: AWS Application Load Balancer
Cacheable by default: No by default. Caches only store responses with unrecognised status codes if explicit freshness (Cache-Control max-age) is given.

What 463 means

An Application Load Balancer returns 463 when the incoming X-Forwarded-For header lists more than 30 IP addresses. That almost always means a proxy loop or a chain of proxies each appending to the header.

What typically causes a 463

Requests looping between proxies (CloudFront to ALB to an app that proxies back to CloudFront, and so on).
Clients or scripts that forge very long X-Forwarded-For values.

Fix it on the server

Find and break the loop; configure proxies to replace rather than append X-Forwarded-For where appropriate.

Fix it as a client or visitor

Do not send your own long X-Forwarded-For header.

Headers that go with 463

Header	Role
`X-Forwarded-For`	The header that exceeded the limit.

Example response

HTTP/1.1 463
Server: awselb/2.0
Content-Type: text/html