Hello, I tried to run sgsnemu in "createif" mode - transfer traffic via tun interface. tun interface created and routing too. But there are no outgoing GTP-U from test machine. (in my scenario sgsnemu on separated server). From gdb it looks, that in cb_tun_ind function ipm->pdp is 0x0, as result gtp_data_req(gsn, ipm->pdp, pack, len); not running. After changes like below, it's start working. Does I correctly understood internal logic? diff --git a/sgsnemu/sgsnemu.c b/sgsnemu/sgsnemu.c index 630733b..cf4aa44 100644 --- a/sgsnemu/sgsnemu.c +++ b/sgsnemu/sgsnemu.c @@ -1462,7 +1462,7 @@ static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause) free(forwarding); } -       ipset((struct iphash_t *)pdp->peer, &addr); +       ipset(iph, &addr);         state = 2;              /* Connected */ If need more test details, please let me know. -- Viktor