Re: Crash related to VLANs in Oct 18th -current

[Roy Marples <roy%marples.name@localhost>]

On 23/10/2017 07:42, Kengo NAKAHARA wrote:
> Hi,
> 
> On 2017/10/22 23:56, Tom Ivar Helbekkmo wrote:
>> Tom Ivar Helbekkmo <tih%hamartun.priv.no@localhost> writes:
>>
>>> That did the trick!  Thank you!  :)
> 
> Thank you for your testing!
> 
>> I'm actually wondering if there may be something else strange going on.
>> Everything works fine -- but I have this dhcpcd running, because one of
>> my VLANs is connected to a network where this machine has to accept a
>> DHCP provisioned IP address from a server.  I run "dhcpcd -q vlan9", and
>> also give it a configuration file that should keep it from doing
>> anything I don't want:
>>
>> allowinterfaces vlan9
>> interface vlan9
>> background
>> persistent
>> hostname_short
>> nogateway
>> nohook resolv.conf, wpa_supplicant, hostname, ntp.conf
>> script /usr/bin/true

You could use script /dev/null or maybe just script by itself, then
dhcpcd won't even try and call the script. Which makes it more efficient.

>>
>> However, after this last upgrade, I keep getting messages from dhcpcd
>> about other interfaces, where this host is the DHCP server, like:
>>
>> Oct 22 16:48:28 barsoom dhcpcd[16236]: vlan2: invalid UDP packet from
>> 172.27.201.1
>> Oct 22 16:48:28 barsoom dhcpcd[16236]: wm0: invalid UDP packet from
>> 172.27.201.1
>>
>> This happens every time a host on one of the other VLANs gets an address
>> from the local DHCP server, and I get this pair of messages; one for the
>> VLAN in question, one for wm0, which is the vlanif with the trunk on it.
>>
>> Running 8.99.1 from about two months ago, these messages did not occur.

This normally indicates a UDP checksum failure.
For future versions, I've improved the message here:
https://roy.marples.name/git/dhcpcd.git/commit/?id=53bad6f740d66108c7412a492819e4c7e17bff51

> 
> Hmm..., sorry, I am not sure about this problem from that information.
> Could you get tcpdump? Of course, if it is not a problem, please do it.
> 
> 
>> roy@n.o
> 
> I think the issue seems to be related to DHCP. Could you think of any
> other way to solve it?

Maybe try disabling hardware processing of UDP checksums on the interface?

Roy