Re: [PATCH net v2 2/3] selftests: forwarding: vxlan_bridge_1d_ipv6: fix test failure with br_netfilter enabled

[Ido Schimmel <idosch@nvidia.com>]

On Fri, Feb 13, 2026 at 01:19:06PM +0000, Aleksei Oladko wrote:
> The test generates VXLAN traffic using mausezahn, where the encapsulated
> inner IPv6 packet has an incorrect payload length set in the IPv6 header.
> After VXLAN decapsulation, such packets do not pass sanity checks in
> br_netfilter and are dropped, which causes the test to fail.
> 
> Fix this by setting the correct IPv6 payload length for the encapsulated
> packet generated by mausezahn, so that the packet is accepted
> by br_netfilter.
> 
> tools/testing/selftests/net/forwarding/vxlan_bridge_1d_ipv6.sh
> lines 698-706
> 
>               )"00:03:"$(           : Payload length
>               )"3a:"$(              : Next header
>               )"04:"$(              : Hop limit
>               )"$saddr:"$(          : IP saddr
>               )"$daddr:"$(          : IP daddr
>               )"80:"$(              : ICMPv6.type
>               )"00:"$(              : ICMPv6.code
>               )"00:"$(              : ICMPv6.checksum
>               )
> 
> Data after IPv6 header:
> • 80: — 1 byte (ICMPv6 type)
> • 00: — 1 byte (ICMPv6 code)
> • 00: — 1 byte (ICMPv6 checksum, truncated)
> 
> Total: 3 bytes → 00:03 is correct. The old value 00:08 did not match
> the actual payload size.
> 
> Fixes: b07e9957f220 ("selftests: forwarding: Add VxLAN tests with a VLAN-unaware bridge for IPv6")
> Signed-off-by: Aleksei Oladko <aleksey.oladko@virtuozzo.com>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>