Disable/Enable Eth adapter in order to establish communication?

asked 2020-09-10 06:26:33 +0000

Santiago gravatar image

I'm using a Media Converter (1000BASE-T1 --> 1000BASE-T) to read an ETH bus. Every time I start Wireshark I find that it is not communicating. So, being the MC and WS "trying" to communicate I have to disable my Eth adapter and enable it again. Only then I will see Eth messages on Wireshark. The problem here is that I need to read the system startup, and it is impossible with this procedure. Is there any way that I can get this to work the first time?


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Trying to get some 'industry standard terminology' here. You have an 'ETH bus', whatever that may be, and a media converter attached to it intended as a network tap probably? Or is this media converter in-line on the ETH link and able to run Wireshark on it as well reading from one of the media converter interfaces? Wireshark, as a passive monitor, does not communicate with the capture interface, it only reads packets from it. It's unclear to me where the capture interface is, so it's unclear how/what link status changes on the media converter ports have on the capture interface.

Jaap gravatar imageJaap ( 2020-09-10 06:46:36 +0000 )edit

Hello, thanks for answering. I'm not an expert in the subject, so my terminology may be a little worng. I'll try to make myself clear: - I have 2 control units (ECU) that use Eth protocol 1000BASE-T1 to communicate. - The computer adapter reads 1000BASE-T protocol. That's why I need a "Media Converter" to convert between protocols. - The configuration is something like this:

ECU1 ---[[1000BASE-T1]]--- MediaConverter ---[[1000BASE-T1]]--- ECU2 

MediaConverter ---[[1000BASE-T]]--- Computer (Wireshark)

The Media Converter acts as the capture interface. Then it sends the converted messages to the computer.

Please tell me if this helps.

Santiago gravatar imageSantiago ( 2020-09-10 07:00:11 +0000 )edit

The Media Converter is similar to a TAP. What model/vendor is it?

Chuckc gravatar imageChuckc ( 2020-09-10 15:44:41 +0000 )edit

The Media Converter is from Technica Engineering, although I cannot find the model in their website. It has 2 RJ45 connections, 8 pin configuration and the 20 pin connector that has the inputs and power source.

Santiago gravatar imageSantiago ( 2020-09-10 16:16:49 +0000 )edit

This is probably best answered by the vendor.
Until then, if the interface Speed/Duplex on the capture system is set to Auto-Negotiate, set it to a static value like 1.0 Gbps Full Duplex.
Do the LEDs on the RJ-45 indicate link status? (not the round LEDs for T1 bus)

Chuckc gravatar imageChuckc ( 2020-09-10 16:39:43 +0000 )edit