# SFP Optics module debugging

**URL:** <https://community.solid-run.com/t/sfp-optics-module-debugging/532>\
**Category:** OCTEON CN9130\
**Created:** [November 28, 2022, 8:18pm UTC](https://community.solid-run.com/t/sfp-optics-module-debugging/532 "2022-11-28T20:18:11Z")\
**Posts on this page:** 1\
**Showing post:** 18

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**Author:** ![bareminimum](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@bareminimum](https://community.solid-run.com/u/bareminimum)\
**Post date:** [April 2, 2023, 10:29am UTC](https://community.solid-run.com/t/sfp-optics-module-debugging/532/18 "2023-04-02T10:29:00Z")

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After reading about the OpenWRT effort here

> [Booting OpenWrt on ClearFog CN9130-Pro - #13 by solarnetone](https://community.solid-run.com/t/booting-openwrt-on-clearfog-cn9130-pro/408/13)

we reran some tests on plain Linux kernel version `6.2.8` with only the new devicetrees added. And again, connecting 2 CN9130 with fiber optics caused very frequent link losses in the order up to a 100 times a second:

```log
[64.370308] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[64.379168] mvpp2 f2000000.ethernet eth0: Link is Down
[64.384398] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[64.393332] mvpp2 f2000000.ethernet eth0: Link is Down
[64.398535] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[64.407406] mvpp2 f2000000.ethernet eth0: Link is Down
[64.412612] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[64.421522] mvpp2 f2000000.ethernet eth0: Link is Down
[64.426819] mvpp2 f2000000.ethernet eth0: Link is Up - 10Gbps/Full - flow control rx
[64.435701] mvpp2 f2000000.ethernet eth0: Link is Down

```

At this point we haven’t managed to find a single working configuration. The only options remain using DACs or some other link partner that is not using marvel hardware.

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_[View the full topic](https://community.solid-run.com/t/sfp-optics-module-debugging/532)._