kernel: in6_delayed_cksum: delayed m_pullup

[Tom Jones]

On Mon, Apr 30, 2018 at 09:54:48AM +0200, Dries Michiels wrote:
> 
> Tom,
> 
> I’m using the igb (intel I210) driver for my LAN interface and the em
> (intel I219-V) driver for the WAN interface.  I use this FreeBSD box
> as my home server so I wouldn’t say that it has a heavy ipv6 workload.
> 

Hi Dries,

Does this bug persist on later snapshots? Or have you stayed with the
same one from the original question?

Could you send me the ifconfig flags lines for igb0 and em0?

like this

$ ifconfig em0
em0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=40098<VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,VLAN_HWTSO>

$ ifconfig igb0
igb0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=6403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6> 


My em interfaces don't have flags for ipv6 checksum offload, I suspect
the issue is from the em side of your network. 

I have tried moving 100GB of v6 tcp through each interface with iperf3
to see if I could stimulate the bug, but no luck so far. I will leave
the test box sitting exposed to my network for a while.

- [tj]