Re: ipv4 route with ipv6 local link nexthop ?

From: Benoit Chesneau <benoitc_at_enki-multimedia.eu>
Date: Wed, 13 Mar 2024 13:40:54 UTC 
Hi Zhenlei,

Thanks for testing;, I was about to start a vm for it. The workaround works as well. I

It seems the same issue when you want to set a route on a n interface that doesn't have any IPs.

eg.` route add -net 10.200.1.1/32 -iface vlan200` will not work without adding an IPv4 to the interface.

Benoît

On Wednesday, March 13th, 2024 at 14:09, Zhenlei Huang <zlei@FreeBSD.org> wrote:

>> On Mar 13, 2024, at 12:19 PM, Zhenlei Huang <zlei@FreeBSD.org> wrote:
>>
>>> On Mar 13, 2024, at 4:36 AM, Benoit Chesneau <benoitc@enki-multimedia.eu> wrote:
>>>
>>> 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
>>
>> I guess that is regression by transition of route(8) to NETLINK.
>
>> Can you please build sbin/route from source without NETLINK and give it another try ?
>>
>> ```
>> # cd /usr/src/sbin/route
>> # setenv MK_NETLINK_SUPPORT no
>> # make
>> ```
>
> Hi Benoit,
>
> I managed to repeat this bug.
>
> As a workaround, add an IPv4 address to the outgoing interface (vlan200 in your case),
> ```
> # ifconfig vlan200 inet x.x.x.x/y
> ```
>
> then retry adding the route
> ```
> # route add -net 10.200.1.1/32 -inet6 fe80::9439:36ff:fef0:7cbd%vlan200
> ```
>
>>> ```
>>>
>>> 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
>>
>> Best regards,
>> Zhenlei