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Bug #16550

closed

Cannot load alternate TCP Congestion Control kernel modules

Added by Glenn Hall about 1 month ago. Updated 7 days ago.

Status:
Resolved
Priority:
Normal
Assignee:
-
Category:
Operating System
Target version:
Start date:
Due date:
% Done:

0%

Estimated time:
Plus Target Version:
25.11
Release Notes:
Force Exclusion
Affected Version:
2.9.0
Affected Architecture:

Description

Since at least the 25.11.b.20251028.1838 beta several TCP CC modules are no longer loading. I have confirmed this is also happening on 25.11.r.20251118.1708. The missing modules are: CDG, Vegas, and CHD. I now only see Cubic, DCTCP, and HTCP available.

Here is the output of my machine running pfSense Plus 25.11.r.20251118.1708:

net.inet.tcp.cc.available:
CCmod D PCB count
cubic 0
dctcp 0
htcp * 25

Here is the output of my machine running pfSense 2.8.1-RELEASE. Prior to pfSense Plus 25.11.b.20251028.1838, the output on my pfSense Plus installation was identical to this:

net.inet.tcp.cc.available:
CCmod D PCB count
cubic 0
cdg 0
vegas 0
hd 0
dctcp 0
htcp * 16

I have the following lines in the loader.conf.local file on both machines:

cc_cdg_load="YES"
cc_htcp_load="YES"
cc_chd_load="YES"
cc_dctcp_load="YES"
cc_hd_load="YES"
cc_vegas_load="YES"


Files

clipboard-202512131614-o03o9.png (29.1 KB) clipboard-202512131614-o03o9.png Jordan G, 12/13/2025 10:14 PM
Actions #1

Updated by Marcos M about 1 month ago

  • Subject changed from Latest Plus 25.11 Beta and RC Do Not Contain Alternative TCP Congestion Control Algorithms to Cannot load alternate TCP Congestion Control kernel modules
$ kldload cc_vegas.ko
kldload: an error occurred while loading module cc_vegas.ko. Please check dmesg(8) for more details.

# dmesg error:
KLD cc_vegas.ko: depends on ertt - not available or version mismatch
linker_load_file: /boot/kernel/cc_vegas.ko - unsupported file type
Actions #2

Updated by Marcos M about 1 month ago

  • Status changed from New to Confirmed
Actions #3

Updated by → luckman212 about 1 month ago

Where can we read more about these alternate congestion control modules and when they might be useful?

Actions #4

Updated by Jordan G 9 days ago

these modules seem to be present in 25.11

Actions #5

Updated by Marcos M 7 days ago

  • Status changed from Confirmed to Resolved
  • Target version set to 2.9.0
  • Plus Target Version set to 25.11
  • Release Notes changed from Default to Force Exclusion
  • Affected Version set to 2.9.0

This is fixed in the release - ertt is now included.

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