Address translation via router
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I'm a software engineer with little clue, so please bear with me here. I have four devices that all have the same, factory-set, IP address, and I need to talk to all of them from the same PC. The boss said "You should be able to do it with a NAT gateway router with port forwarding", which sounds more like buzzword bingo than any actually useful advice. I think most cheapo home WiFi routers can do this, but I'm not sure what to look for. It needs to be reasonably cheap, have at least 5 ethernet ports (1 PC, 4 devices), and ideally be configurable so I can assign IP addresses to specific ethernet ports (so regardless of which device is plugged into port 3, it always have the same alias). Please help?
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I'm a software engineer with little clue, so please bear with me here. I have four devices that all have the same, factory-set, IP address, and I need to talk to all of them from the same PC. The boss said "You should be able to do it with a NAT gateway router with port forwarding", which sounds more like buzzword bingo than any actually useful advice. I think most cheapo home WiFi routers can do this, but I'm not sure what to look for. It needs to be reasonably cheap, have at least 5 ethernet ports (1 PC, 4 devices), and ideally be configurable so I can assign IP addresses to specific ethernet ports (so regardless of which device is plugged into port 3, it always have the same alias). Please help?
Orjan Westin wrote:
all have the same, factory-set, IP address
Then they cannot co-exist in the same network. Try to find out how to configure their IPs properly, everything else will be a WTF.
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Orjan Westin wrote:
all have the same, factory-set, IP address
Then they cannot co-exist in the same network. Try to find out how to configure their IPs properly, everything else will be a WTF.
That's why I need address translation. If I need to get one router for each, that's fine too. But I can't configure their IPs, as this is for a factory test setup. Get four devices off the production line, put them in, run the tests. The tests take a few minutes, but are not limited by the PC, so if I can connect four devices and run the tests in parallel, it'll be an enormous time-saver.
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That's why I need address translation. If I need to get one router for each, that's fine too. But I can't configure their IPs, as this is for a factory test setup. Get four devices off the production line, put them in, run the tests. The tests take a few minutes, but are not limited by the PC, so if I can connect four devices and run the tests in parallel, it'll be an enormous time-saver.
You're in deep yogurt, then, because - by definition - no two devices with the same IP address is allowed to exist on one network. If you're planning to ship units that have to have the same IP address, your product will have a very short life cycle. But... If, for purpose of factory testing, you need to do testing on 4 identical units at once, all with the same address, you have to configure each unit to listen for and respond to test commands on a specific port, and configure the test environment to use fixed addressing with no DHCP service active. You can then spoof the test network into thinking it's hosting one machine with 4 ports, and configure the main router to use port forwarding to talk to each of the machines on its distinct port. A far better approach would be to either change the IP addresses of the UUTs and run the tests sequentially, or rewrite the tests to run on the UUT as it should be done, and again change the UUT IP address to be unique on the network. The advantage of the latter method is that the test code is downloaded to the UUT and allowed to run, without interaction from the other three machines or the host, until the test is complete. After a decent interval, the test host machine can poll each of the UUTs for test results. If they've blocked you somehow from changing the device IP addresses, tell them to enjoy carnal knowledge of a rolling donut, and go find a job with a real company that has a chance of remaining in business for a while. This one's doomed.
Will Rogers never met me.
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You're in deep yogurt, then, because - by definition - no two devices with the same IP address is allowed to exist on one network. If you're planning to ship units that have to have the same IP address, your product will have a very short life cycle. But... If, for purpose of factory testing, you need to do testing on 4 identical units at once, all with the same address, you have to configure each unit to listen for and respond to test commands on a specific port, and configure the test environment to use fixed addressing with no DHCP service active. You can then spoof the test network into thinking it's hosting one machine with 4 ports, and configure the main router to use port forwarding to talk to each of the machines on its distinct port. A far better approach would be to either change the IP addresses of the UUTs and run the tests sequentially, or rewrite the tests to run on the UUT as it should be done, and again change the UUT IP address to be unique on the network. The advantage of the latter method is that the test code is downloaded to the UUT and allowed to run, without interaction from the other three machines or the host, until the test is complete. After a decent interval, the test host machine can poll each of the UUTs for test results. If they've blocked you somehow from changing the device IP addresses, tell them to enjoy carnal knowledge of a rolling donut, and go find a job with a real company that has a chance of remaining in business for a while. This one's doomed.
Will Rogers never met me.
Sorted: One router per device. The WAN address of the routers statically set to unique addresses, which the PC uses as addresses to the devices. The LAN address on the routers is set to be the same, i.e. the Default Gateway of the device, and the routers are set to do port forwarding to the device address. Adds a few hundred bucks to the cost of the test station, which isn't too bad considering the test equipment is tens of thousands. No need to make any custom settings on any devices, they already come with a static address and a default gateway set up. (The tests aren't run on the UUTs; the test PC is ordering the UUT to transmitt/measure received signals at various power levels andfrequencies.)
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Sorted: One router per device. The WAN address of the routers statically set to unique addresses, which the PC uses as addresses to the devices. The LAN address on the routers is set to be the same, i.e. the Default Gateway of the device, and the routers are set to do port forwarding to the device address. Adds a few hundred bucks to the cost of the test station, which isn't too bad considering the test equipment is tens of thousands. No need to make any custom settings on any devices, they already come with a static address and a default gateway set up. (The tests aren't run on the UUTs; the test PC is ordering the UUT to transmitt/measure received signals at various power levels andfrequencies.)
That's a workable solution, Orjan, given the constraints you're stuck with. :)
Will Rogers never met me.