I've recently been assigned to work on a diagnostic program done in C++ which communicates with a piece of electronic equipment. Our normal scenario involves communicating via an RS232 interface, but I've been asked to make our program work over ethernet, source code having been done in Visual Basic. After much thrashing about trying to get the code to work and continuing to get 10049 Winsock errors when I tried to connect, I tried pinging the switch. From the computer the VB program is running on, I can see the switch via ping, nslookup, tracert, and pathping (I was going down the list of programs) and I can do this via URI or IP address. From my laptop, sending the same commands fails every time. They're both using the same network cable and the same USB-to-Ethernet device (I've been swapping them between tests) but one can see the switch and the other cannot. I'm working on the programming end, but the ping results makes me think that there might be a network issue stymieing me. wry grin I'm not much of a network guy, so I'm appealing to expert assistance. Both computers are running Windows XP if that helps. The connection is to an "IP-RS8" device which then connects to our VCU-C units. Each unit is accessible via URI or IP address on the desktop computer we usually have connected to the units (it's running the older VB program that I was asked to lift the networking code from). The connection is made via a USB-to-Ethernet adapter so as to leave the regular Ethernet port available for connecting to the company network. Hmm... come to think of it, I've probably been confusing the issue, talking about pinging "the switch" rather than indicating that it's the devices. My apologies. Communication is generally done with a DLL that uses Winsock functions to make queries for data from the VCU and then to receive. I'm failing when connecting. I haven't found anything on the firewall which should block these commands, but I'll keep poking. I don't know if it's potentially relevant, but on the desktop, the adapter maps to Local Area Connection 3 while on the laptop, it consistently maps to Local Area Connection 2. Currently reading up on DHCP. IPConfig /all results: Desktop Host Name . . . . . . . . . . . . : AMERDAEXXXXXX Primary Dns Suffix . . . . . . . : amer.example.com Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : COMPANY.com amer.example.com atle.example.com cone.example.com apac.example.com scan.example.com bYX.example.com Ethernet adapter Local Area Connection X: Connection-specific DNS Suffix . : amer.example.com Description . . . . . . . . . . . : Broadcom NetXtreme XYxx Gigabit Controller Physical Address. . . . . . . . . : YY-XX-YB-XX-XX-XX Dhcp Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : XYY.XXX.XY.XXX Subnet Mask . . . . . . . . . . . : XXX.XXX.XXY.Y Default Gateway . . . . . . . . . : XYY.XXX.XY.X DHCP Server . . . . . . . . . . . : XY.XXX.XXY.XX DNS Servers . . . . . . . . . . . : XY.XXX.XXY.XX XY.XXY.XXY.XX Primary WINS Server . . . . . . . : XY.XXX.XXY.X Secondary WINS Server . . . . . . : XY.XXY.XXY.X Lease Obtained. . . . . . . . . . : Thursday, July XX, XYXX XY:XX:XX AM Lease Expires . . . . . . . . . . : Sunday, July XX, XYXX XY:XX:XX AM Ethernet adapter Local Area Connection X: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : ASIX axYYYYX USBX.Y to Fast Ethernet Adapter Physical Address. . . . . . . . . : YY-XY-BY-YX-XY-AY Dhcp Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : XY.Y.Y.X Subnet Mask . . . . . . . . . . . : XXX.XXX.XXY.Y Default Gateway . . . . . . . . . : XY.Y.Y.X DHCP Server . . . . . . . . . . . : XY.Y.Y.XY DNS Servers . . . . . . . . . . . : XY.Y.Y.X Lease Obtained. . . . . . . . . . : Thursday, July XX, XYXX XY:XX:XY AM Lease Expires . . . . . . . . . . : Tuesday, August YX, XYXX XX:XY:XY AM Laptop Windows IP Configuration Host Name . . . . . . . . . . . . : AMERLAFYYXXYX Primary Dns Suffix . . . . . . . : amer.example.com Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : COMPANY.com amer.example.com atle.example.com cone.example.com apac.example.com scan.example.com bYX.example.com Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : amer.example.com Description . . . . . . . . . . . : Intel(R) 82567LM Gigabit Network Connection Physical Address. . . . . . . . . : YY-XY-BY-DY-XB-YX Dhcp Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : XYY.XXX.XY.XY Subnet Mask . . . . . . . . . . . : XXX.XXX.XXY.Y Default Gateway . . . . . . . . . : XYY.XXX.XY.X DHCP Server . . . . . . . . . . . : XY.XXX.XXY.XX DNS Servers . . . . . . . . . . . : XY.XXX.XXY.XX XY.XXY.XXY.XX Primary WINS Server . . . . . . . : XY.XXX.XXY.X Secondary WINS Server . . . . . . : XY.XXY.XXY.X Lease Obtained. . . . . . . . . . : Thursday, July XX, XYXX XX:XX:XX AM Lease Expires . . . . . . . . . . : Sunday, July XX, XYXX XX:XX:XX AM Ethernet adapter {XYXAAYXX-YEDY-XXYX-YYEX-BYXYXXYEEYEX}: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Nortel IPSECSHM Adapter - Packet Scheduler iniport Physical Address. . . . . . . . . : XX-XX-XX-XX-XX-YY Dhcp Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : Y.Y.Y.Y Subnet Mask . . . . . . . . . . . : Y.Y.Y.Y Default Gateway . . . . . . . . . : Ethernet adapter Leaf Networks Adapter: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Leaf Networks Adapter Physical Address. . . . . . . . . : YY-FF-FA-BC-YF-AY Dhcp Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : X.XYY.XY.XX Subnet Mask . . . . . . . . . . . : XXX.Y.Y.Y Default Gateway . . . . . . . . . : Ethernet adapter Local Area Connection 3: Media State . . . . . . . . . . . : Media disconnected Description . . . . . . . . . . . : Bluetooth LAN Access Server Driver Physical Address. . . . . . . . . : YY-FX-AX-YA-BY-CA Ethernet adapter Wireless Network Connection 2: Media State . . . . . . . . . . . : Media disconnected Description . . . . . . . . . . . : Intel(R) WiFi Link 5300 AGN Physical Address. . . . . . . . . : YY-XX-YA-CX-FC-YE Ethernet adapter Local Area Connection 2: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : ASIX ax88772 USB2.0 to Fast Ethernet Adapter Physical Address. . . . . . . . . : YY-XY-BY-YX-XY-AY Dhcp Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : XYX.XYY.X.X Subnet Mask . . . . . . . . . . . : XXX.XXX.XXX.Y Default Gateway . . . . . . . . . :