ipv4 route with ipv6 local link nexthop ?

From: Benoit Chesneau <benoitc_at_enki-multimedia.eu>
Date: Tue, 12 Mar 2024 20:36:09 UTC 
On latest freebsd 14.0 release , I am trying to join an ipv4 address over an IPV6 local link using the following command :

`route add -net 10.200.1.1/32 -inet6 fe80::9439:36ff:fef0:7cbd%vlan200`

But I get the following error:

```
route add -net 10.200.1.1/32 -inet6 fe80::9439:36ff:fef0:7cbd%vlan200
add net 10.200.1.1: gateway fe80::9439:36ff:fef0:7cbd%vlan200 fib 0: Invalid argument
```

ping6 to `fe80::9439:36ff:fef0:7cbd%vlan200` works. What I am doing wrong? Configuration of the interface is the following:

```
vlan200: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
options=4600703<RXCSUM,TXCSUM,TSO4,TSO6,LRO,RXCSUM_IPV6,TXCSUM_IPV6,MEXTPG>
ether fe:d9:dd:2d:35:c5
inet6 fe80::fcd9:ddff:fe2d:35c5%vlan200 prefixlen 64 scopeid 0x5
groups: vlan
vlan: 200 vlanproto: 802.1q vlanpcp: 0 parent interface: iavf0
media: Ethernet autoselect (10Gbase-SR <full-duplex>)
status: active nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL
```

Benoît