Switching

hi,

I'm working on a Juniper EX4100 and I've managed to get them both stacked using 10G-SR SFPs in PIC1.

However, I now need a 1G-SX uplink within PIC2, for some reason this is up up, but I do not get link from the upstream device (QFX5100). Replacing this with a 10G-SR SFP both ends however works. I feel its fair to conclude that 1G-SX SFP in a Juniper EX4100 PIC2 is my issue here - has anyone else had this? The hardware suggests this is supported, but am I missing configuration?

FPC 0            REV 08   650-134056   FA0823AN0176      EX4100-48P-CHAS
  CPU                     BUILTIN      BUILTIN           FPC CPU
  PIC 0          REV 08   BUILTIN      BUILTIN           48x10M/100M/1G Base-T
  PIC 1          REV 08   650-134056   FA0823AN0176      4x1G/10G/25G SFP/SFP+/SFP28
    Xcvr 2       REV 01   740-021308   C2305126935       SFP+-10G-SR
    Xcvr 3       REV 01   740-021308   C2305126931       SFP+-10G-SR
  PIC 2          REV 08   650-134056   FA0823AN0176      4x1G/10G SFP/SFP+
    Xcvr 0       REV 01   740-011613   F2033908882       SFP-SX
    Xcvr 1       REV 01   740-011613   F2033908809       SFP-SX
    Xcvr 2       REV 01   740-011613   F2033298563       SFP-SX
    Xcvr 3       REV 01   740-011613   F2033908803       SFP-SX

EX4100-48P> show interfaces ge-0/2/0 terse
Interface               Admin Link Proto    Local                 Remote
ge-0/2/0                up    up
ge-0/2/0.0              up    up   eth-switch

EX4100-48P> show interfaces diagnostics optics ge-0/2/0 | match pow
    Laser output power                        :  0.2890 mW / -5.39 dBm
    Laser receiver power                      :  0.2170 mW / -6.64 dBm

EX4100-48P> show chassis fpc pic-status
Slot 0   Online       EX4100-48P-CHAS
  PIC 0  Online       48x10M/100M/1G Base-T
  PIC 1  Online       4x1G/10G/25G SFP/SFP+/SFP28
  PIC 2  Online       4x1G/10G SFP/SFP+
Slot 1   Online       EX4100-48P-CHAS
  PIC 0  Online       48x10M/100M/1G Base-T
  PIC 1  Online       4x1G/10G/25G SFP/SFP+/SFP28
  PIC 2  Online       4x1G/10G SFP/SFP+

QFX5100> show interfaces ge-0/0/12 terse 
Interface               Admin Link Proto    Local                 Remote
ge-0/0/12               up    down
ge-0/0/12.0             up    down eth-switch

QFX5100> show interfaces diagnostics optics ge-0/0/12 | match pow 
    Laser output power                        :  0.2930 mW / -5.33 dBm
    Laser receiver power                      :  0.2276 mW / -6.43 dBm

Not sure if the  QFX5100 is the same but on the ex4650 you have to tell it ports are 1g and it works in block of 4

XXXXXX@XXXXXX# show chassis 

fpc 0 {
    pic 0 {
        port 40 {
            speed 1G;
        }
    }
}

for ports 40-43 

let me know how youo get on. 
Have you tried the same 1g gig optics in each end ?

Regards

Simon

hi Simon,

Thank you for your thoughts.

We did try the same 1G optics each end, did a whole matrix and swapped around.

We even tried the set chassis command you've listed above, however the speed option is only 10G, 1G is not available - saying this now perhaps its hidden and I could have tried.

I decided to go through the open problems on the JunOS version we chose to run, 22.4R1, and low and behold I found this:
https://prsearch.juniper.net/problemreport/PR1657766

https://www.juniper.net/documentation/us/en/software/junos/release-notes/22.4/junos-release-notes-22.4r1/topics/open-issues/ex-open-issues-22.4r1.html

So the fix on this version is to disable auto-neg on the upstream QFX interface.

I'm going to try a later version but I cannot see this PR as resolved in 23.2R1 so the workaround may still apply.

hi Simon,

We upgraded the software and the bug still exists.

Therefore for anyone reading 23.2R1 still does not solve this and no-auto-neg must be set up the upstream device.