Sometimes no LAN connection when I turn on my 8600

PhilM · August 30

Sometimes when I turn on my 8600 it doesn't get a LAN connection, and of course SMARTSDR can't connect to it. The on/off button at this point does or at least seems to do nothing. I have to turn off the power supply and restart it to get the radio working normally again.

Should I be doing something other than off/on by power supply?

Phil, NC3S

VE7ATJ_Don · August 30

Hi Phil… could you provide us with more information about how your radio and pc/laptop are connected? That would help us with diagnosis.

E.g. Is the radio directly connected to the PC/Mac? Is the radio directly connected to the router (with a cable)? Is the PC/Mac directly connected to the router? Is the PC/MAC connecting via Wi-Fi? What symptoms are you seeing that tell you the radio is not getting a LAN connection?

Thanks.

PS… re: turning off the radio — since you have a non-M model, it's best to think of the Flex as a radio 'server', with the PC/MAC as a client. In that sense, it works much better if you simply leave the server on and attached to the network all the time, then connect the client (PC/MAC) when you want to do 'radio stuff'. Many of us leave the server on 24x7 with no problems/ill effects.

PhilM · August 31

Both my windows pc and the flex are using wired network connections. There is no direct connection between the pc and the radio either. When this occurs my router is showing that the radio doesn't have an active connection.

Erik Carling EI4KF · August 31

My solution to this was to set a fixed IP address in the router for the radio. Make it outside of the router's DHCP allocation. Example my router's DHCP scope is 192.168.68.10 to 100. I have the radio on .104

You could try it and see if there is any difference. If not, nothing lost and you could ask the Help Desk.

One other aspect of my 8000 series radio over my 6400 is that if starting the radio from PSU off, I must strictly enforce the instruction to wait 2 minutes from PSU on before turning on the radio.

PhilM · August 31

Erik

My router is configured to always assign the mac address of the Flex8600 to the same IP address and that appears to work well. Internally routers use the mac address to distribute packets between devices, and the mac address of the flex should be static and appears to be. Looking at the configuration between devices, typically the Flex should have a listener, listening on a port and SMARTSDR being the client then connects to the listener port on the flex to create a socket, when this occurs all is good. All that being said it seems to imply to me that the radio doesn't have an active listener for the client to connect to since the router is showing no active connection between router and radio.

This error condition occurs once to twice a week. So its not too bad to handle by just restarting the power.

Phil, NC3S

Mike-VA3MW · September 1

Hi Phil

This is something related to your network and not the radio (99% of the time). You may wish to try a different cable.

By any chance are you using a gigabit switch? If so, can you try a different switch or even a 100mb switch and see if the problem goes away?

73

PhilM · September 1

Yes I am using a 2.5 gb switch I don't think I have anything less than a gigabit switch. But I do think trying a static IP with no dhcp involvement might solve things. I need to figure what the proper values are for my router first.

Phil, NC3S

Mike-VA3MW · 2:18AM

It sounds like the DHCP process isn't completing correctly. It might be related the the process and the autonegotiation process which both happen at the same time.

PhilM · 2:16PM

Yes, it does sound like a dhcp delay issue or maybe something in the flex firmware that implements tcpip on the flex not waiting long enough for a response. Since I cant make the issue reoccur I think the best option is the static IP configuration. I have an issue open with eero, my router brand, to assist me in determining which ip address I need since some of the values I see in their router app dont agree with the settings I see.

Phil, NC3S

Mike-VA3MW · 2:34PM

It might not be the radio firmware but more of a switch issue. After all DHCP on the radio works fine on many other switches without issue.

Since the radio does not run at 2.5GB, autonegotiation has to happen.

When a 2.5G switch port is connected to a 100 Mbps client, autonegotiation should ideally detect and downshift to 100 Mbps full duplex. However, problems can arise if either the client or the switch does not fully comply with the autonegotiation standard, or if there’s a mismatch in configuration (e.g., one end is set to auto, and the other is manually configured).

This can lead to duplex mismatches, degraded throughput, or intermittent connectivity — which can in turn affect DHCP operation. If the link is unstable or slow to negotiate, the DHCP request from the client may time out, fail, or require retries. In high-density environments with many 100 Mbps devices, this can cause longer boot times or a flood of DHCP requests that briefly overload the DHCP server or switch CPU. Proper configuration and testing are critical when mixing legacy clients with modern high-speed switches.

Not all switches are created equal we have learned and it is easy to assume they are.

If it was a managed switch, you could log into the switch and see what is really going on. Are ports flapping, are there collisions, etc. I would reach out to the switch manufacturer and see if they have others complaining about DHCP failing.

The quick test would be to replace the 2.5 switch with another switch and see if the symptoms change.

Another thought. Do you have a switch plugged into a switch? Where is your DHCP server hosted? This is when a network topology helps to tell the full story.

Sometimes no LAN connection when I turn on my 8600

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