Strange Networking Issue

Hi both !

In fact all this seems to be very logic, as the POE 802.3ax standard requires the device to be able to tell the power supplier its need in terms of power consumption and some other information such as if it is .3af, .3at …

I guess that during this process, the IP link is not already switched on by the supplier as it must ensure the needs are respected before starting the link…

In such a way, however the cable is physically connected, if the link is not switched on by the supplier, it is considered as false by the module…

Using the retry sequence I put in my program, it often takes about 2 or 3 retry before it says OK, and effectively when debugging, i do not observe any retry…

What I did not test and will have to, is the connectionchanged event during uptime, and check if the event is correctly thrown and how it influence my other running threads (TCP Listener, Web Site and so on…). If you already did some tests, do not hesitate to share !

@ LouisCpro Hi, when you are talking about retrying 2-3 times before it says ok, do you mean in relation to: NetworkInterfaceExtension.AssignNetworkingStackTo(Eth1)? One of the issues I have is that I get no errors during configuration of the EthernetBuiltIn. As far as it is concerned everything is good to go.

do you mean in relation to: NetworkInterfaceExtension.AssignNetworkingStackTo(Eth1)? [/quote]


Do not remember exactly but I guess it was effectively there…Regarding to the provided code, you’ll see I put something retry/while in several part of the process to ensure all will be fine at the end…however it will not serve, it is few things but a gain in stability…

Hello Louis

Your code suppose that

 will throw an exception if something is wrong.

I observe no exception but what I am seeing is that: if i run the board with Visual Studio attached, (after a deployment) it runs well, when the board is launched without VS, then It may have problem, board does not answer to ping... if I relaunched the board using Visual, then no problem. 

It seems that a soft reset is necessary in order to have a proper ethernet initialization... Any idea?

I am using the ethernet built in interface from an EMX

Sniffing the network with wireshark does not show anything different between soft reset and power on reset.
In each case, Wireshark shows two IGMPv2 sentences.

If I start the board without connecting the cable and connect it after startup, ping is ok…

@ leforban -

Are you using a fixed or DHCP Address ?

Most of the time it’s fixed (but it has to work also when dhcp is on)

Of course yes ! But sometimes i noticed that the negociation for an IP address takes a while, and depending to the internal implementation of cable connected, it should probably be also an issue…

I am again facing this problem today… again the switch is a Moxa with POE devices connected…

Your MOXA reference is ?

…Did you check it always comply with 10 MB ?

The moxa is an EDS-205… will check if it is 10Mb complianty

It’s supposed to be 10/100 base TX compliant ???

Some posts before, you said that posering up your board and then connecting the plug was OK for the ping … Always the case ?

did you try to put your Ethernet activation later in your boot sequence, or even make a pause before proceeding ???

It’s still the case yes.
On this configuration, it works only if the board is started without cable connected

This is really weird. I also use your try pattern…

Let’s go I finally have the problem for the first time on my desktop in the office so let’s analyse what is happening.

I see correctly the IGMPV2 when cable is connected and ip is affected (static ip).
When I try to ping I get no answer.
Desktop sends ARP message but no one answers…

See line 79 and 86…

Any idea?