I have circuit board board that is made up of:
USB <-> LAN9500 <-> MII <-> PHY IC

LAN9500 is a USB to MII IC. The LAN9500 do contain one mac address. PHY IC is a special IC that also contains a MAC address.

So there is total 2 MAC address on this circuit board.
Togheter they generate a small network. The circuit board is not connected to the copper. The reason for this is because I need to load a firmware into the PHY before it works on the copper.

With WireShark I see that the PHY is broadcasting network packages. I have a small program that broadcast network packages:
* These is not shown in WireShark.
* The sendto function does not give any error.

So the packages I try to send disappears somehow in the linux kernel. I do suspect that linux kernel see that something is wrong with the link, and decide not to send the package.

Any ideas?

# dmesg
[82754.087355] usb 5-1.1: new high-speed USB device number 7 using xhci_hcd
[82754.106134] smsc95xx v1.0.4
[82754.188761] smsc95xx 5-1.1:1.0: eth1: register 'smsc95xx' at usb-0000:02:00.0-1.1, smsc95xx USB 2.0 Ethernet, 5a:71:10:58:df:ad
[82754.273593] ADDRCONF(NETDEV_UP): eth1: link is not ready

# ifconfig eth1 netmask up

# ifconfig -a
eth1 Link encap:Ethernet HWaddr 5a:71:10:58:df:ad
inet addr: Bcast: Mask:
RX packets:185 errors:0 dropped:185 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8510 (8.5 KB) TX bytes:0 (0.0 B)

# sudo tcpdump -i eth1
16:36:26.083072 00:b0:52:00:00:01 (oui Unknown) > Broadcast, ethertype Unknown (0x88e1), length 60:
0x0000: 0062 a000 b052 0400 0000 0000 0000 0000 .b...R..........
0x0010: 0000 0000 0000 0000 0000 0000 0000 0000 ................
0x0020: 0000 0000 0000 0000 0000 0000 0000 ..............

# sudo ethtool eth1
Settings for eth1:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Link partner advertised link modes: 100baseT/Full
Link partner advertised pause frame use: Symmetric
Link partner advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
Transceiver: internal
Auto-negotiation: on
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes

# sudo ethtool -i eth1
driver: smsc95xx
version: 22-Aug-2005
firmware-version: smsc95xx USB 2.0 Ethernet
bus-info: usb-0000:02:00.0-1.1
supports-statistics: no
supports-test: no
supports-eeprom-access: yes
supports-register-dump: no

 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.

#include <arpa/inet.h>
#include <linux/if_packet.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/ether.h>

#define MY_DEST_MAC0	0xFF
#define MY_DEST_MAC1	0xFF
#define MY_DEST_MAC2	0xFF
#define MY_DEST_MAC3	0xFF
#define MY_DEST_MAC4	0xFF
#define MY_DEST_MAC5	0xFF

#define DEFAULT_IF	"eth1"
#define BUF_SIZ		1024

int main(int argc, char *argv[])
	int sockfd;
	struct ifreq if_idx;
	struct ifreq if_mac;
	int tx_len = 0;
	char sendbuf[BUF_SIZ];
	struct ether_header *eh = (struct ether_header *) sendbuf;
	struct iphdr *iph = (struct iphdr *) (sendbuf + sizeof(struct ether_header));
	struct sockaddr_ll socket_address;
	char ifName[IFNAMSIZ];
	/* Get interface name */
	if (argc > 1)
		strcpy(ifName, argv[1]);
		strcpy(ifName, DEFAULT_IF);

	/* Open RAW socket to send on */
	if ((sockfd = socket(AF_PACKET, SOCK_RAW, IPPROTO_RAW)) == -1) {

	/* Get the index of the interface to send on */
	memset(&if_idx, 0, sizeof(struct ifreq));
	strncpy(if_idx.ifr_name, ifName, IFNAMSIZ-1);
	if (ioctl(sockfd, SIOCGIFINDEX, &if_idx) < 0)
	/* Get the MAC address of the interface to send on */
	memset(&if_mac, 0, sizeof(struct ifreq));
	strncpy(if_mac.ifr_name, ifName, IFNAMSIZ-1);
	if (ioctl(sockfd, SIOCGIFHWADDR, &if_mac) < 0)

	/* Construct the Ethernet header */
	memset(sendbuf, 0, BUF_SIZ);
	/* Ethernet header */
	eh->ether_shost[0] = ((uint8_t *)&if_mac.ifr_hwaddr.sa_data)[0];
	eh->ether_shost[1] = ((uint8_t *)&if_mac.ifr_hwaddr.sa_data)[1];
	eh->ether_shost[2] = ((uint8_t *)&if_mac.ifr_hwaddr.sa_data)[2];
	eh->ether_shost[3] = ((uint8_t *)&if_mac.ifr_hwaddr.sa_data)[3];
	eh->ether_shost[4] = ((uint8_t *)&if_mac.ifr_hwaddr.sa_data)[4];
	eh->ether_shost[5] = ((uint8_t *)&if_mac.ifr_hwaddr.sa_data)[5];
	eh->ether_dhost[0] = MY_DEST_MAC0;
	eh->ether_dhost[1] = MY_DEST_MAC1;
	eh->ether_dhost[2] = MY_DEST_MAC2;
	eh->ether_dhost[3] = MY_DEST_MAC3;
	eh->ether_dhost[4] = MY_DEST_MAC4;
	eh->ether_dhost[5] = MY_DEST_MAC5;
	/* Ethertype field */
	eh->ether_type = htons(ETH_P_IP);
	tx_len += sizeof(struct ether_header);

	/* Packet data */
	sendbuf[tx_len++] = 0xde;
	sendbuf[tx_len++] = 0xad;
	sendbuf[tx_len++] = 0xbe;
	sendbuf[tx_len++] = 0xef;

	/* Index of the network device */
	socket_address.sll_ifindex = if_idx.ifr_ifindex;
	/* Address length*/
	socket_address.sll_halen = ETH_ALEN;
	/* Destination MAC */
	socket_address.sll_addr[0] = MY_DEST_MAC0;
	socket_address.sll_addr[1] = MY_DEST_MAC1;
	socket_address.sll_addr[2] = MY_DEST_MAC2;
	socket_address.sll_addr[3] = MY_DEST_MAC3;
	socket_address.sll_addr[4] = MY_DEST_MAC4;
	socket_address.sll_addr[5] = MY_DEST_MAC5;

	/* Send packet */
	int lenr = 0;
	lenr = sendto(sockfd, sendbuf, tx_len, 0, (struct sockaddr*)&socket_address, sizeof(struct sockaddr_ll));
	if (lenr < 0){
	    printf("Send failed\n");
	    printf("Send %d bytes\n", lenr);

	return 0;