Multipath support not enabled in kernel

[kc834]

Is your feature request related to a problem? Please describe.
Please enable multipath support

[kevchaud@kevchaud-8QH6043 ~]$ sudo ip netns add INET
[kevchaud@kevchaud-8QH6043 ~]$ sudo ip netns exec INET ip link set dev lo up
[kevchaud@kevchaud-8QH6043 ~]$ sudo ip netns exec INET ip route add default nexthop via 41.10.0.1 nexthop via 41.11.0.1
Error: Multipath support not enabled in kernel.
[kevchaud@kevchaud-8QH6043 ~]$ uname -r
5.15.90.1-microsoft-standard-WSL2

Describe the solution you'd like
Update config: CONFIG_IP_ROUTE_MULTIPATH=y

Describe alternatives you've considered
I have built a custom kernel by modifying the instructions here https://perso.uclouvain.be/tom.barbette/mptcp-on-windows-with-wsl2/ but it would be nice to not have to do that.

Additional context
None

[tcaiazzi]

Hi all,

Any news about this?

[soredake]

@kelsey-steele Hi! I've seen that you've fixed #8302, can you look at this issue too, please?

[tcaiazzi]

It seems that newer WSL kernel versions have CONFIG_IP_ROUTE_MULTIPATH enabled.

My kernel version:

uname -a
Linux thinkpad 6.6.114.1-microsoft-standard-WSL2 #1 SMP PREEMPT_DYNAMIC Mon Dec  1 20:48:54 UTC 2025 aarch64 aarch64 aarch64 GNU/Linux

The sysctl is available:

sysctl net.ipv4.fib_multipath_hash_policy
net.ipv4.fib_multipath_hash_policy = 0