Direct ethernet connection w/laptop?

Wondering if I configure a KiwiSDR for a static ip address could I connect it directly to an ethernet port on a laptop, and then access it without a network router as the intermediary. I also wonder if such a direct connection is even "legal" hardware-wise, i.e. would it cause damage to the ethernet interface(s)? I suppose if it were OK, I would have to change the network properties on the ethernet adapter in the laptop to assign it an ip address on the same subnet as the KiwiSDR.

If this were possible, it would be highly useful for in-the-field testing of HF antennas, assuming I also had a battery in place to power the KiwiSDR.

Comments

  • OK, I apologize for that post, the answer was ALREADY there on the operating instructions page...what follows is a copy/paste for future reference...I will give it a try even though it states that it does not seem to work with Windows 10...

    "Point-to-point Ethernet connection to a host computer

    Note: This procedure seems not to work with Windows 10 anymore. There is no workaround.

    Some users simply want to install an Ethernet cable directly between the Kiwi and a laptop or PC and not involve other equipment (like a router) and not involve the Internet. This might be because they are traveling or only have a wireless connection between their PC and an Internet access device that has no Ethernet ports. We now have a solution for this case.

    Starting with the v1.47 release the Kiwi software uses something called avahi-autoipd which takes over when the Kiwi is unable to locate a DHCP server to get an IP address for the Ethernet port. A random-but-unique link-local IP address in the 169.254.0.0/16 range is then assigned to the Ethernet. Similar software present on all modern Macs and PCs does the same thing. Now the PC and Kiwi should be able to talk to each other. Since you don't know what IP address has been assigned to the Kiwi you instead use the name kiwisdr.local. On Windows this currently requires the Bonjour/mDNS package to be installed with the workaround described here. Macs are already setup. So now you can connect to the Kiwi by using kiwisdr.local:8073/ and kiwisdr.local:8073/admin to administrate.

    It's also now possible to observe the Beagle LEDs to see what IP address was assigned.

    Note that it takes more than 60 seconds after the Kiwi boots before it decides there is no DHCP and it should assign a link-local address. So please be patient before trying to connect from the PC."

  • Does this also require a 'cross-over' Ethernet cable, or are these things no longer needed with modern PC's ?

  • For a long time most Ethernet twisted-pair PHYs have supported auto MDI-X which makes crossover cables unnecessary: https://en.wikipedia.org/wiki/Medium-dependent_interface

  • I was successful with a point-to-point ethernet connection with my Win10 laptop. Nothing fancy at all, but for someone like me with limited knowledge about networking it was quite pleasing to get this to work. I am posting explicit instructions here for future reference, for myself and anyone else who may come across this in the future...

    1) I assigned a static ip address to the KiwiSDR, via the admin page network settings. Just to be safe, and possibly avoid losing access after my direct ethernet connection experiment, I assigned it the SAME ip address already assigned to it by the DHCP server on the LAN (10.1.1.232 in this specific instance). I power cycled the Kiwi to make sure I could still connect to it through the normal LAN pathway, with its static ip address.

    2) I Connected the KiwiSDR directly to the laptop via an ethernet cable. Opening a command prompt (elevated to admin privileges), I used the 'ipconfig' command to identify the auto-confg ip address of the ethernet adapter in the laptop, in this case it was 169.254.204.45. Next, I added an entry to the routing table in windows that forces all connections to the Kiwi (at 10.1.1.232) to go through the ethernet adapter...by typing the following line...

    route add 10.1.1.232 mask 255.255.255.255 169.254.204.45

    3) Once I did that I used 'route print" to verify that the routing table now contained the special entry to access the Kiwi through the ethernet port, and I also verified that a ping to 10.1.1.232 yielded a normal response. Finally, I opened the browser and was able to connect directly to the Kiwi using the 10.1.1.232 address it was set to. Success!

    For me, this make the KiwiSDR a wonderful tool for field testing on HF antennas, checking for noise added by a feedline etc etc. Note, the routing table entry will go away as soon as the laptop is rebooted, unless I tell it to make the entry permanent by adding -p after the route command, i.e. 'route -p add 10.1.1.232 mask 255.255.255.255 169.254.204.45'....but one would need to be careful about that, of course.

  • Wow, thanks! I hadn't thought about that (and didn't realize Windows, like Linux/Unix, made routing changes relatively easy. The documentation now references your post!

  • edited April 1

    I didn't realise that route would work.

    Have used "route add" for a long while unaware it could be via an APIPA interface for a range outside the subnet. It's not obvious from the docs either https://docs.microsoft.com/en-us/windows-server/troubleshoot/how-to-use-automatic-tcpip-addressing-without-a-dh

    "Note that the computer cannot communicate with computers on other subnets, or with computers that do not use automatic private IP addressing."

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