Hello, On Mon, Nov 30, 2015, at 12:55, Bjørn Mork wrote: > Generating a random ifid for devices with no L2 header > at all, allowing such devices to take part in IPv6 > autoconfiguration. The tuntap driver is one example of > a driver where such an ifid would be useful. > > Note that as there is no persistence, new addresses > will be generated every time an interface is brought up: > > # ip -6 addr show dev tun0 > 8: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 state > UNKNOWN qlen 500 > inet6 fe80::eef2:111c:f270:92ba/64 scope link > valid_lft forever preferred_lft forever > # ip link set tun0 down > # ip link set tun0 up > # ip -6 addr show dev tun0 > 8: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 state > UNKNOWN qlen 500 > inet6 fe80::eec0:48d0:6b52:8835/64 scope link > valid_lft forever preferred_lft forever > > Signed-off-by: Bjørn Mork <bj...@mork.no> > --- > I'm planning raw-ip support for the qmi_wwan driver. And > the feedback from primary users (ModemManager++) is that > a headerless netdev is preferred over a fake ethernet > device. The current plan is to model this after 'tun' > devices, using ARPHRD_NONE as type. > > But these devices will need an IPv6 link local address for > full SLAAC support. I am therefore wondering if an approach > like this patch will be acceptable, or if I should look for > some other solution?
I see no problem with the patch as it eases operating those devices. I would also suggest storing the ifid in the inet6_dev so it does only change during device creation and destruction. Otherwise I would recommend to use stable privacy addresses to generate the link local addresses. EUI-48 based LL creation should hopefully not be used anymore soon. Thanks, Hannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
