[j-nsp] Trouble with 100G link MX204 <-> Dell S4100F-ON

[Aaron Gould]

On the topic of FEC mode....thought I'd share something I found a while back when testing the ACX5448 with an MX960

The ACX5448 40 gig interface defaulted to FEC74... the MX960 40 gig interface on an MPC7E-MRATE module default to FEC "NONE"

40 gig link would not come up

agould at lab-960> show system information
Model: mx960
Family: junos
Junos: 17.4R2-S1.2
Hostname: lab-960

agould at eng-lab-5448> show system information
Model: acx5448
Family: junos
Junos: 18.3-20180825.3
Hostname: eng-lab-5448

After reconfig of FEC mode on ACX5448 to NONE, interface came up and we passed ping tests...

agould at eng-lab-5448> show interfaces et-0/1/0 | grep "fec mode"
  Ethernet FEC Mode  :                   NONE

agould at lab-960> show interfaces et-0/1/0 | grep "fec mode"
  Ethernet FEC Mode  :                   NONE


[edit]
root at eng-lab-5448# set interfaces et-0/1/0 gigether-options fec ?
Possible completions:
  fec74                FEC74 enabled
  fec91                IEEE 802.3bj Clause 91, Reed-Solomon FEC (RS-FEC)
  none                 FEC disabled


-Aaron