I have a PC which connects to a network by both wired cable and wireless. Of course, it has 2 IP Addresses : 192.168.5.111 and 192.168.5.112. (Subnet mask 255.255.255.0)
As usual, the PC picks the wired-IP(192.168.5.111) as its main-IP while the wireless-IP is almost "disabled". That means:
1/ No other PC could ping to the wireless IP
2/ No other PC could make a TCP connection to wireless IP.
3/ When I broadcast to "192.168.5.255" or send any UDP packet, the recipients never
see that sender's address as the wireless IP
This is expected behavior. The odd happened when I unplugged the cable to remove the wired-network.
1/ Other PCs could now ping my wireless IP
2/ Other PCs could now make TCP connection to wireless IP
3/ BUT : When I broadcasted to "192.168.5.255", no other PC in LAN received my packet.
When other PCs broadcasted to "192.168.5.255", my PC received nothing as well.
I tried broadcasted to "255.255.255.255" and things worked as expected. But, recipients see my IP as 192.168.5.111 (the unplugged IP) instead of 192.168.5.112 (my wireless IP). And in other hand, I know it's not a good solution to broadcast to "255.255.255.255" as many experts recommended.
I've stepped 1 step farther when I open the network devices and disabled the "Ethernet(Wired)" device. After that I could do the No.3/ and get things worked as expected.
So my question is: Is my wired-connection cached somewhere in my PC that I could not broadcast normally by wireless-IP without the wired-device disabled? Is there any workaround to fix this ?
PRACTICAL DATA :
This is the routeTable when I have both network adapter enabled (wired & wireless):
===========================================================================
Interface List
11...5c ff 35 0b d8 34 ......Atheros AR8131 PCI-E Gigabit Ethernet Controller
14...00 26 82 a5 62 82 ......Broadcom 802.11n Network Adapter
1...........................Software Loopback Interface 1
12...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
13...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface
===========================================================================
IPv4 Route Table
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.5.1 192.168.5.102 30
0.0.0.0 0.0.0.0 192.168.5.1 192.168.5.104 20
127.0.0.0 255.0.0.0 On-link 127.0.0.1 306
127.0.0.1 255.255.255.255 On-link 127.0.0.1 306
127.255.255.255 255.255.255.255 On-link 127.0.0.1 306
192.168.5.0 255.255.255.0 On-link 192.168.5.102 286
192.168.5.0 255.255.255.0 On-link 192.168.5.104 276
192.168.5.102 255.255.255.255 On-link 192.168.5.102 286
192.168.5.104 255.255.255.255 On-link 192.168.5.104 276
192.168.5.255 255.255.255.255 On-link 192.168.5.102 286
192.168.5.255 255.255.255.255 On-link 192.168.5.104 276
224.0.0.0 240.0.0.0 On-link 127.0.0.1 306
224.0.0.0 240.0.0.0 On-link 192.168.5.102 286
224.0.0.0 240.0.0.0 On-link 192.168.5.104 276
255.255.255.255 255.255.255.255 On-link 127.0.0.1 306
255.255.255.255 255.255.255.255 On-link 192.168.5.102 286
255.255.255.255 255.255.255.255 On-link 192.168.5.104 276
===========================================================================
And this is routeTable when I unplug the cable of wired network:
===========================================================================
Interface List
11...5c ff 35 0b d8 34 ......Atheros AR8131 PCI-E Gigabit Ethernet Controller
14...00 26 82 a5 62 82 ......Broadcom 802.11n Network Adapter
1...........................Software Loopback Interface 1
12...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
13...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface
===========================================================================
IPv4 Route Table
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.5.1 192.168.5.102 30
127.0.0.0 255.0.0.0 On-link 127.0.0.1 306
127.0.0.1 255.255.255.255 On-link 127.0.0.1 306
127.255.255.255 255.255.255.255 On-link 127.0.0.1 306
192.168.5.0 255.255.255.0 On-link 192.168.5.102 286
192.168.5.102 255.255.255.255 On-link 192.168.5.102 286
192.168.5.255 255.255.255.255 On-link 192.168.5.102 286
224.0.0.0 240.0.0.0 On-link 127.0.0.1 306
224.0.0.0 240.0.0.0 On-link 192.168.5.102 286
255.255.255.255 255.255.255.255 On-link 127.0.0.1 306
255.255.255.255 255.255.255.255 On-link 192.168.5.102 286
===========================================================================
route print
) to check if it looks incorrect when you’re unplugged. Also, WiFi being “disabled” while connected via Ethernet is in no way normal.