udp bind nic and ping 192.168.199.1 ,gnb receive reply, One more thing is gnb send data to uetun

openair3/GTPV1-U/gtpv1u_eNB.c

@@ -1343,7 +1343,7 @@ void *gtpv1u_eNB_process_itti_msg(void *notUsed) {
           sgw_s1u_teid                        = 0x01;
           stack_req.apiType                   = NW_GTPV1U_ULP_API_SEND_TPDU;
           stack_req.apiInfo.sendtoInfo.teid   = sgw_s1u_teid;
-          in_addr_t upf_addr=0xc0a8c7DF;
+          in_addr_t upf_addr=0xc0a80a0a;//0xc0a8c7DF;
           //stack_req.apiInfo.sendtoInfo.ipAddr = gtpv1u_ue_data_p->bearers[data_req_p->rab_id - GTPV1U_BEARER_OFFSET].sgw_ip_addr;
           stack_req.apiInfo.sendtoInfo.ipAddr = upf_addr; 
           rc = nwGtpv1uGpduMsgNew(

openair3/UDP/udp_eNB_task.c

@@ -34,6 +34,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <net/if.h> 
 
 #include <pthread.h>
 
@@ -166,7 +167,11 @@ int udp_eNB_create_socket(int port, char *ip_addr, task_id_t task_id)
   } else {
     sin.sin_addr.s_addr = inet_addr(ip_addr);
   }
-
+  struct ifreq interface;
+  strncpy(interface.ifr_ifrn.ifrn_name, "enx000ec6c0a3ac", sizeof("enx000ec6c0a3ac"));
+  if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, (char *)&interface, sizeof(interface))  < 0) {
+         perror("SO_BINDTODEVICE failed");
+  }
   if ((rc = bind(sd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in))) < 0) {
     close(sd);
     AssertFatal(rc >= 0, "UDP: Failed to bind socket: (%s:%d) address %s port %d\n",