when a context is active, the interface name is typically ppp0. If you try to run pppd for some other device/interface, the kernel ppp driver prints an error because it can't register ppp0. It looks like it's assumed that ppp* interface names are reserved for the ppp_driver. Can the tun interface name be changed to eg. ofono0?

> actually we are using ppp%d syntax to assign the network interfaces. So > the kernel does the numbering. This is a bug in pppd and not ours. > > Looking at the pppd code, it seems to hardcodes ppp0. So please complain > to them for assuming that a certain device name is owned by them. > pppd requests the ppp driver to create a network interface with the ioctl PPPIOCNEWUNIT. If the parameter passed to the ioctl is -1, the ppp driver will allocate the unit itself. Because it's the first network interface created by the ppp driver, and the ppp driver doesn't know about the tun interface, it's choosing 0. Check ppp_create_interface() in ppp_generic.c in the kernel to see how this is done. So it seems the ppp driver reserves the ppp%d interface names.