OT: strange network problem

[Erez D]

On Tue, Jan 11, 2022 at 3:14 PM Ohad Levy <ohadlevy at gmail.com> wrote:

>
>
> On Tue, Jan 11, 2022 at 11:26 AM Erez D <erez0001 at gmail.com> wrote:
>
>>
>>
>> On Tue, Jan 11, 2022 at 9:29 AM Ohad Levy <ohadlevy at gmail.com> wrote:
>>
>>>
>>>
>>> On Tue, Jan 11, 2022 at 9:19 AM Erez D <erez0001 at gmail.com> wrote:
>>>
>>>> The windows 169.25. ip is from APIPA and not from any DHCP server
>>>> (ipconfig does not specify a dhcp server).
>>>> to be on the safe side I verified udp port 67 is unused on my mac (via
>>>> netstat, fuser and socat)
>>>>
>>>> what boggles me is why can't the window machine access the router and
>>>> get an ip when the mac is sleeping
>>>>
>>>> as the AP switch is layer 2, i would susspect the switch disables the
>>>> windows machin for some reason,
>>>> e.g. it sees the same mac address from another port or detects abuse of
>>>> somewhat from the windows eth port
>>>> however i do not understand how is this related to the mac sleeping
>>>>
>>>> I thought the AP switch maybe defective but puting another GB switch
>>>> instead causes the same results ...
>>>>
>>>
>>> can you run tcpdump on your router? does it show the dhcp requests from
>>> your windows machine?
>>>
>> Alas, No. I know it is sacrilege but I use a hot cable modem/router.
>> I do not have hardware that can support 500Mb to be used as a linux
>> firewall ...
>>
> openwrt :)
>
I'm probably getting old, in my time running openwrt required hardware to
run on  ;-)

>
> but technically, if you have a 3rd machine, you should be able to see dhcp
> requests being broadcasted on layer2
>
> I'll try that though i do not understand why there should be a difference
if my mac is up or not ...
Thanks

>
>> Thanks,
>> Erez.
>>
>>
>>>> why do you thing HOMEGROUP is related ? it is a higher layer protocol
>>>> when the problems seems to me on layer 2
>>>>
>>>> Thanks,
>>>> Erez
>>>>
>>>>
>>>>
>>>>
>>>> On Tue, Jan 11, 2022 at 8:36 AM <borissh1983 at gmail.com> wrote:
>>>>
>>>>> On Monday, 10 January 2022 19:30:55 IST Erez D wrote:
>>>>> > I've encountered a network problem
>>>>> >
>>>>> > i have a mac and a win10 machine connected to a 4 port Gbit wifi6 AP
>>>>> > (switch mode).
>>>>> > a third eth from the AP goes to the router which is also a DHCP
>>>>> server
>>>>> >
>>>>> > everything works well until the mac goes to sleep.
>>>>> > when the mac goes to sleep, the win10 machine looses it's ip address
>>>>> > which becomes a 169. address
>>>>> >
>>>>> > as soon as i wake the mac up, the win machine regain a valid
>>>>> 10.0.0.x ip
>>>>> >
>>>>> > i tried to replace the AP with a 4 port switch and got same results
>>>>> >
>>>>> >
>>>>> > any idea ?
>>>>> >
>>>>>
>>>>> IP in the  169.254.0.0/16 range is related to bonjour protocol , it
>>>>> is a link local communication.
>>>>>
>>>>> your windows would move to a bonjur ip in many cases but most common
>>>>> that can happen if your machine has a bonjour service enabled and an
>>>>> Ethernet card with dhcp that can not get an ip from the router.
>>>>>
>>>>> 1. Check if when the mac is running your windows machine got it's ip
>>>>> from the mac and not from the router. in some cases mac can have dhcpd
>>>>> running on it, if that is the case you should disable it if you do not need
>>>>> it.
>>>>> 2. Check if homegroup is enabled on win10, if it is disable it (by
>>>>> version 1803 it is no longer active by default, but you could have hacked
>>>>> to enable it).
>>>>>
>>>>>
>>>>> _______________________________________________
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>>>> Linux-il at cs.huji.ac.il
>>>> http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
>>>>
>>>
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