On Saturday 12 December 2015 22:43:45 Maximilian Engelhardt wrote: > Hello, > > I'm using a Lenovo TinkPad Edge E135 notebook that has a Realtek wired > network interface inbuilt. Under some conditions the nic doesn't work after > changing the mac address. > > It took me some time to figure out that it makes a difference if I (re)boot > my notebook with or without the power supply plugged in. When I boot the > system with the power supply plugged in everything does work fine as > expected. But if I boot with the power supply unplugged and I change the > mac address the network card doesn't work. > > > This is how I am testing and how I can reproduce the behavior on my system: > > * Boot Linux (Debian stable with a newer kernel) > * Network is still turned off, only loopback is enabled by default in my > setup. * I run the following commands: > ip link set dev eth0 address 00:12:0c:96:a7:2e # a randomly generated mac > ip link set dev eth0 up > ip addr add dev eth0 10.0.252.50/24 > ip route add default via 10.0.252.1 > > When the notebook is booted with the power supply plugged in the network is > working as expected, e. g. I can ping the gateway. > > But when the notebook was booted without the power supply attached the > network is not working e. g. pinging the gateway doesn't get any replies. > > I found two ways to get the network working from this state (beside > rebooting with power plugged in): > > * If I enable promiscous mode the network connections are working again: > # ip link set dev eth0 promisc on > > * Alternatively I can set the same mac address again while the interface is > up: > # ip link set dev eth0 address 00:12:0c:96:a7:2e # same mac as before > > > So it seems like a mac filter in the network card is not set up right. > > > Attached are dmesg output of a boot with and without power supply attached > as well as the output of lspci -vvv. > > > Please let me know If you need more information. > > Thanks, > Maxi
Hello, Anyone had a look at this? I can confirm that the problem is still present in kernel 4.4.2. I just did a quick tcpdump and found out that packets are transmitted fine, but the replay of the other end gets lost somewhere in the nic/driver e. i. it seems to never reach the kernel network stack. Please let me know if you need more information from me. Thanks, Maxi
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