I found reason why my telnet under PPP driver failed. This is because I used netmask 255.255.255.255 :-( But in ipin.c there is: if (dst == 0xffffffff || (nif->if_local_ip && ((dst | nif->if_mask) == 0xffffffff))) { bcast = 1; ..... if (bcast) NutNetBufFree(nb); Now all works OK. Best wishes, Tarmo Fimberg