steamcmd doesn't work with IPv6 disabled via kernel

[ZizzyZizzy]

Your system information

ii steamcmd:i386 0~20130205-1 i386 Command-line interface for Valve's Steam

Ubuntu 18.04

• Opted into Steam client beta?: [No]
• Have you checked for system updates?: [Yes]

Please describe your issue in as much detail as possible:

steamcmd fails to download if IPv6 is completely disable via kernel params

[  0%] Checking for available updates...
[----] Verifying installation...
Steam Console Client (c) Valve Corporation
-- type 'quit' to exit --
Loading Steam API...CreateBoundSocket: failed to create socket, error EAFNOSUPPORT (97)
OK.

Connecting anonymously to Steam Public...CreateBoundSocket: failed to create socket, error EAFNOSUPPORT (97)
Retrying. . .
CreateBoundSocket: failed to create socket, error EAFNOSUPPORT (97)
Retrying. . .
CreateBoundSocket: failed to create socket, error EAFNOSUPPORT (97)
Retrying. . .
CreateBoundSocket: failed to create socket, error EAFNOSUPPORT (97)
CreateBoundSocket: failed to create socket, error EAFNOSUPPORT (97)
Retrying. . .
CreateBoundSocket: failed to create socket, error EAFNOSUPPORT (97)
CreateBoundSocket: failed to create socket, error EAFNOSUPPORT (97)
FAILED login with result code No Connection
ERROR! Failed to request AppInfo update, not online or not logged in to Steam.

Steps for reproducing this issue:

1. Disable IPv6 in sysctl and grub
2. Reboot
3. Attempt to use steamcmd

[dinsdalepiranha]

I am suddenly seeing this with the Steam Client today. Same OS with IPv6 disabled.

[booth-f]

It is recommended that you not disable IPv6. Even if your network does not have working IPv6, some OS services depend on IPv6 being enabled in the kernel for proper functionality.

Please re-enable IPv6 in the kernel, reboot your machine and try running steamcmd again.