Community discussions

MikroTik App
 
pculverhouse
just joined
Topic Author
Posts: 2
Joined: Thu Mar 02, 2023 5:31 pm

CRS305-1G-4S+IN 5 Port Desktop Switch config issues

Thu Mar 02, 2023 5:40 pm

Hi,

I have a Mikrotik CRS305-1G-4S+IN 5 Port Desktop Switch. I need to use it to convert a SPF+ 1G fibre port to RJ45 copper between two local fixed IP addresses.

I have a host (IP 192.168.0.100) and a client (IP 192.168.0.101) that need to communicate using TCP/IP. I have an existing copper unmanaged switch that I connect these two devices using copper RJ45 and I can establish comms and it all works (a BrainBoxes SW-005).

I did the same using an SPF+ fibre (1GB OM3 LC interface) plugged into port 1, with my computer (the host 192.168.0.100) on the PoE RJ45 port. I was expecting them to connect. But they don't.

I have tried to grapple with the documentation, but I'm a hardware engineer and have little comms experience.

Any suggestions most welcome.

Phil
 
User avatar
mkx
Forum Guru
Forum Guru
Posts: 11439
Joined: Thu Mar 03, 2016 10:23 pm

Re: CRS305-1G-4S+IN 5 Port Desktop Switch config issues

Thu Mar 02, 2023 7:37 pm

By default, CRS devices are configured to act as switches between all ports. So the problem you're experiencing is most probably not configuration error.
I don't have a CRS305, but I believe that the RJ45 port is intended for management. Thus it might not be part of switch ports group.

Mikrotiks are quite notorious for sub-optimal support for SFP modules. And if they are supported, speed autonegotiation might not work. So verify these things:
  1. is SFP module detected and recognized?
  2. did port speed negotiate to 1Gbps (you're writing about 1Gbps all over so I'm assuming the optical link peer supports 1Gbps and not 10Gbps).
    If it didn't, try to disable autonegotiation and set speed to 1Gbps
If you're using SFP+ RJ45 module to connect the copper device, repeat the steps written above also for the RJ45 port.
 
pculverhouse
just joined
Topic Author
Posts: 2
Joined: Thu Mar 02, 2023 5:31 pm

Re: CRS305-1G-4S+IN 5 Port Desktop Switch config issues

Fri Mar 03, 2023 3:08 pm

Many thanks for the observations. I'll try your suggestions.

Phil
 
mbovenka
Member
Member
Posts: 338
Joined: Mon Oct 14, 2019 10:14 am

Re: CRS305-1G-4S+IN 5 Port Desktop Switch config issues

Fri Mar 03, 2023 5:18 pm

As you run the SFP+ port at 1G (and so probably are using an SFP): did you disable autonegotiation and set the port to 1G FDX? If you don't, the link will seem to come up, but no traffic will flow. Been there, done that...

Who is online

Users browsing this forum: Bing [Bot], friend2809, toffline, zdiv and 31 guests