Will cloudflare block some AWS ip?

I am trying connect to a cloudflare IP from a AWS server by sending a https request.
It always timeout.
But from other servers, like digitalocean and hetzner, as well as from local, the request works well.
I checked AWS security settings, it seems nothing block the request.
So, does cloudflare block some AWS ips or I missed something??

Many thanks

host name?

with IP (cloudflare) directly. my IP

Those are IPs, not hostnames… what error are you receiving. Cloudflare isn’t blocking a connection to origins. If there’s a specific error/ origin error you should debug it based on the error received.


hostname: arb1. arbitrum.io

I am using Https (js) to send out a request.
I changed the “lookup” function so that the DNS can directly give the specific cloudflare IP (, for a faster speed).
This code works well on local but fails on AWS server.
It simply gives:
problem with request connect ETIMEDOUT

Testing locally that host name is redirected to the root domain.

curl -Ikv https://arb1.arbitrum.io/
*   Trying
* Connected to arb1.arbitrum.io ( port 443 (#0)
* ALPN: offers h2,http/1.1
* (304) (OUT), TLS handshake, Client hello (1):
* (304) (IN), TLS handshake, Server hello (2):
* (304) (IN), TLS handshake, Unknown (8):
* (304) (IN), TLS handshake, Certificate (11):
* (304) (IN), TLS handshake, CERT verify (15):
* (304) (IN), TLS handshake, Finished (20):
* (304) (OUT), TLS handshake, Finished (20):
* SSL connection using TLSv1.3 / AEAD-CHACHA20-POLY1305-SHA256
* ALPN: server accepted h2
* Server certificate:
*  subject: C=US; ST=California; L=San Francisco; O=Cloudflare, Inc.; CN=arbitrum.io
*  start date: Apr 30 00:00:00 2023 GMT
*  expire date: Apr 29 23:59:59 2024 GMT
*  issuer: C=US; O=Cloudflare, Inc.; CN=Cloudflare Inc ECC CA-3
*  SSL certificate verify ok.
* using HTTP/2
* h2h3 [:method: HEAD]
* h2h3 [:path: /]
* h2h3 [:scheme: https]
* h2h3 [:authority: arb1.arbitrum.io]
* h2h3 [user-agent: curl/7.88.1]
* h2h3 [accept: */*]
* Using Stream ID: 1 (easy handle 0x13b80da00)
> Host: arb1.arbitrum.io
> user-agent: curl/7.88.1
> accept: */*
< HTTP/2 301
HTTP/2 301
< date: Mon, 10 Jul 2023 05:30:49 GMT
date: Mon, 10 Jul 2023 05:30:49 GMT
< location: https://arbitrum.io
location: https://arbitrum.io

This works well, but I want to direct to
This is done by change the lookup function

But you appear to have selected an IP address Cloudflare owns which isn’t even listening on port 443. Use one of the IP addresses assigned to the domain in question if you feel you must hard code it.

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