OT: strange network problem

[Erez D]

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 ...

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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>
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