Error with ipv6

# Health check:
#     - adding [-i tailscale0 -j MARK --set-mark 0x40000/0xff0000] in v6/filter/ts-forward: running [/nix/store/zpl4wlvc9a4ziq7b6ccrpxzn5mwc3frn-iptables-1.8.10/bin/ip6tables -t filter -A ts-forward -i tailscale0 -j MARK --set-mark 0x40000/0xff0000 --wait]: exit status 2: Warning: Extension MARK revision 0 not supported, missing kernel module?
ip6tables v1.8.10 (nf_tables): MARK: bad value for option "--set-mark", or out of range (0-4294967295).

Issue: https://github.com/tailscale/tailscale/issues/13863

3 methods to fix:

  1. Upgrade Linux kernel
  2. Change Tailscale to nftables: https://github.com/tailscale/tailscale/issues/13863#issuecomment-2752301262
TS_DEBUG_FIREWALL_MODE=nftables
  1. Disable ipv6
sudo sysctl net.ipv6.conf.all.disable_ipv6=1