Stateless hetzner Firewall rules - with WHM Server causing issue.

Hatrix Hoster

• August 17, 2025 17:01

Hi  

Inbound Firewall rules:

• 2020, 80, 443 (TCP) :  2020 is for SSH port
• 2048-9216, 465 (TCP)
• 20, 21, 25 (TCP)
• 587, 993, 995 (TCP)
• 53, 853, 49152-65535 (TCP)
• 32768-65535 with source 53, 123 (UDP)
• 53 (UDP)
• ICMP

Outbound Firewall rules:

• 80, 443, 7080 (TCP)
• 53, 853, 873 (TCP)
• 20, 21, 2703 (TCP)
• 25, 587, 465 (TCP)
• 23, 2089, 27017 (TCP)
• 32768-65535 with ack TCP Flag (TCP)
• 53, 6277, 24441 (UDP)
• 123 (UDP)
• 32768-65535 (UDP)
• ICMP

I have the following firewall rules currently set for my whm server at hetzner robot. The issue I am facing is that, sometime the WHM portal I mean the :2087 runs very slow, normally like navigating from one tab to another.(note: server is new and no any high load- dedicated server)

But when I check the same with cpanel, then I found it to be perfect. no lag, no slowness.

However, in WHM face performance issue, I don't know if I have mis-configured my firewall rules which is conflicting on it. Please can you try figuring out what is the actual issue here?

 

When I turn off or disable the hetzner firewall rules from the robot and depends only on the csf firewall everything runs smooth. but the hetzner stateless firewall causing the issue with performance specially with WHM.

• 

  Hatrix Hoster

  • August 17, 2025 17:06

  sometime seeing things like : 

  ERR_CONNECTION_TIMED_OUT in the website or hostname when certain request took longer time.
  
  and sometime the terminal in root whm account face the issue of :

  Error: The WebSocket handshake failed.

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• 

  cPRex Jurassic Moderator

  • August 18, 2025 14:04

  Hey there!  It seems like you've identified the issue - have you spoken with Hetzner about their tool to see if they had any ideas?  If the system works well with that external firewall disabled then the problem wouldn't be related to cPanel & WHM.

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