Re: [Cerowrt-devel] cerowrt-3.10.34-4 dev build released

[Dave Taht <dave.taht@gmail.com>]

On Sat, Apr 5, 2014 at 5:49 AM, Neil Shepperd <nshepperd@gmail.com> wrote:
>> Sounds like you are going to stick with -4 for a bit?
>
> Actually, this is the first time I've tried cerowrt on a router. But
> yeah, I'll stick with the current version unless you come out with a new
> patch to try.

Thx. I am hoping this is the *last* priority 1 bug cerowrt has.

but_fixing_it_is_going_to_be_pita.

I_confess_to_"embedded_fatigue".

>> what I've been doing is mounting a usb stick, and just running continuously
>> on the stick
>>
>> tcpdump -s 128 -i ge00 -w ge00.cap &
>> tcpdump -s 128 -i sw00 -w sw00.cap &
>>
>> This definately hurts performance...
>>
>> And it's probably time to do a tcpdump on the connected device as well.
>>
>
> Update: I did this, and experienced the hang again. A first look at the
> tcpdump output on sw00 shows a sudden reduction in traffic at 20:40:54,
> so I assume that's probably the time of the event. After that, I see
> many DHCP and ARP requests arriving, but no responses leaving the interface.

It_would_be_nice_to_see_10sec_of_these_captures_before_and_after.

>
> In fact, I don't see anything leaving except, oddly, some DNS responses
> (which are indeed received by my laptop). I also see some EAPOL stuff on
> both the router and laptop at roughly the same time, so I guess that's
> getting through, but I don't know the direction.
>
> I think next time I'll try with -Pin/-Pout to separate incoming and
> outgoing packets properly...

Tis easier_to_sort_in_wireshark_against_one_capture,IMHO.

I_have_been_looking_for_failed_syn_attempts_and_retries_as_a_key_indicator
that_something_Bad_happened.

>> Hmm. OK, this brings back the device driver into the equation... I
>> WAS seeing dhcp and arp requests "getting through" from the captures,
>> and it seemed like arp in particular was getting through...
>
> So I guess this is only half right? What I see in syslog is dnsmasq
> saying it has sent a packet, but it doesn't make it onto the interface.
> Apart from DNS packets, so I don't know what to make of that.

It_is_possible_there_are_a_variety_of_failure_modes.

I_am_not_entirely_convinced_this_is_actually_a_wifi_specific_failure.

can_you_try_ssh_to_the_router_during_a_failure,and/or_accessing
the_web_admin_interface?and/or_trying_to

if_you_are_not_using_babel_disable_it.It_makes_a_lot_of_updates
to_the_routing_table.that_might_be_malfunctioning..

(I_really_need_a_keyboard_that_recovers_from_damp_weather.)

> Neil



-- 
Dave Täht

Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.html