How to test if an sfp is working on juniper qfx5100

My manager asked me to test if a 3rd party sfp is working on juniper !! what tests can i run on it to compare different company test equipment ?

Can i use a loopback and test the optics for heat and packet counter (packet loss) can i pump traffic from the switch ?

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    Dec 25, 2018 at 8:54

2 Answers 2

  1. Check the manual/datasheets - both the switch and the transceiver should state what they're compatible with. If you're using a range of different optics it makes a lot of sense to maintain a compatibility table.
  2. Check the log - the transceiver should be logged as incompatible if it is.
  3. A loopback test makes sure the link can come up - don't do it without M/R/STP active though.
  4. On 850 nm transceivers (-SX/-SR) you can very often see the red glow on the transmitter side (a short glance won't hurt, just don't stare for a length of time). This means the transceiver is active and looking for a link. Transmitters with a very tight band can be made visible with a digicam or phone camera. Obviously, don't try this with a high-power transmitter (-E/-Z), you won't see the 1310 or 1550 nm light anyway.
  5. Actually transferring data across the link tests both transceivers and the fiber. With an incompatible SFP the link won't even come up.

The best way (in my opinion) to test is:
1. Build fiber connection between two devices ( Juniper <> Second Device)
2. Plug the SFP modules and try to bring the ports UP / Connected.
3. Assign private IP addresses from the same network on both interfaces:
Juniper: /29 <> Second Device / 29
4. Try to ping eachother. If there is ICMP reply you will know for sure that the sfp transceiver will work.

If you have some concerns, do not hesitate to ask.
Could you share the SFP transceiver - model / wavelength / speed etc... ?

Thank you!

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