ios 13 dhcpd vs dhclient stale lease

classic Classic list List threaded Threaded
6 messages Options
Reply | Threaded
Open this post in threaded view
|

ios 13 dhcpd vs dhclient stale lease

Ted Unangst-6
I'm not sure where the bug is exactly (seems probable it could be an apple
problem), but for the record...

When my laptop roams from my home wifi to my phone hotspot, it retains the
same IP it had on the home network, which doesn't work with the phone network.
Running dhclient manually results in it supposedly getting the same IP:
        iwm0: bound to 10.3.3.63 from 172.20.10.1

The only way to get a working IP is to delete the dhclient.leases file, then
run it again. At last:
        iwm0: bound to 172.20.10.6 from 172.20.10.1

I'm not sure what can be done. Does ios echo back our suggestion incorrectly?
Does it return some result that dhclient misinterprets? No idea. We could
detect this condition perhaps? Anyway, there's a workaround for affected
people.

Reply | Threaded
Open this post in threaded view
|

Re: ios 13 dhcpd vs dhclient stale lease

Sebastian Benoit-3
Ted Unangst([hidden email]) on 2019.10.06 14:33:17 -0400:

> I'm not sure where the bug is exactly (seems probable it could be an apple
> problem), but for the record...
>
> When my laptop roams from my home wifi to my phone hotspot, it retains the
> same IP it had on the home network, which doesn't work with the phone network.
> Running dhclient manually results in it supposedly getting the same IP:
> iwm0: bound to 10.3.3.63 from 172.20.10.1
>
> The only way to get a working IP is to delete the dhclient.leases file, then
> run it again. At last:
> iwm0: bound to 172.20.10.6 from 172.20.10.1
>
> I'm not sure what can be done. Does ios echo back our suggestion incorrectly?
> Does it return some result that dhclient misinterprets? No idea. We could
> detect this condition perhaps? Anyway, there's a workaround for affected
> people.

I think ifconfig  output in the home wifi and the hotspot wifi would be
helpful for debugging, and the pcap file from

  tcpdump -s 1500 -w /tmp/wifi.pcap -i <if> port bootps or port bootpc

while you move from one network to the other, and then run dhclient by hand.

/B.

Reply | Threaded
Open this post in threaded view
|

Re: ios 13 dhcpd vs dhclient stale lease

kwesterback


> On Oct 6, 2019, at 2:59 PM, Sebastian Benoit <[hidden email]> wrote:
>
> Ted Unangst([hidden email]) on 2019.10.06 14:33:17 -0400:
>> I'm not sure where the bug is exactly (seems probable it could be an apple
>> problem), but for the record...
>>
>> When my laptop roams from my home wifi to my phone hotspot, it retains the
>> same IP it had on the home network, which doesn't work with the phone network.
>> Running dhclient manually results in it supposedly getting the same IP:
>>    iwm0: bound to 10.3.3.63 from 172.20.10.1
>>
>> The only way to get a working IP is to delete the dhclient.leases file, then
>> run it again. At last:
>>    iwm0: bound to 172.20.10.6 from 172.20.10.1
>>
>> I'm not sure what can be done. Does ios echo back our suggestion incorrectly?
>> Does it return some result that dhclient misinterprets? No idea. We could
>> detect this condition perhaps? Anyway, there's a workaround for affected
>> people.
>
> I think ifconfig  output in the home wifi and the hotspot wifi would be
> helpful for debugging, and the pcap file from
>
>  tcpdump -s 1500 -w /tmp/wifi.pcap -i <if> port bootps or port bootpc
>
> while you move from one network to the other, and then run dhclient by hand.
>
> /B.
>

And the leases file when it is misbehaving.

 Running with -L on both networks (saving the different versions!) to record what dhclient thinks it is getting and configuring would also help diagnosis. And the dhclient.conf file just to add suspenders to the belt and road initiative.

Unfortunately I've got no idea how to gather useful info on the ios side.

.... Ken

Reply | Threaded
Open this post in threaded view
|

Re: ios 13 dhcpd vs dhclient stale lease

Ted Unangst-6
In reply to this post by Ted Unangst-6
Ted Unangst wrote:
> I'm not sure where the bug is exactly (seems probable it could be an apple
> problem), but for the record...

I think this was fixed with an apple update? Nothing in the release notes of
course, but it doesn't seem to happen anymore.

Reply | Threaded
Open this post in threaded view
|

Re: ios 13 dhcpd vs dhclient stale lease

kwesterback
On Wed, Oct 30, 2019 at 04:14:53PM -0400, Ted Unangst wrote:
> Ted Unangst wrote:
> > I'm not sure where the bug is exactly (seems probable it could be an apple
> > problem), but for the record...
>
> I think this was fixed with an apple update? Nothing in the release notes of
> course, but it doesn't seem to happen anymore.
>

That corresponds to all the glowing praise iOS 13.X.Y is getting. :-)

.... Ken

Reply | Threaded
Open this post in threaded view
|

Re: ios 13 dhcpd vs dhclient stale lease

matteo filippetto
In reply to this post by Ted Unangst-6
Il giorno mer 30 ott 2019 alle 21:15 Ted Unangst <[hidden email]> ha
scritto:

> Ted Unangst wrote:
> > I'm not sure where the bug is exactly (seems probable it could be an
> apple
> > problem), but for the record...
>
> I think this was fixed with an apple update? Nothing in the release notes
> of
> course, but it doesn't seem to happen anymore.



Same here, after updating iPhone to ios 13.2 the issue is fixed.

I had problem also from macbook to iPhone so I think it’s not an openbsd
related problem.

Regards



> --
Matteo Filippetto