10G Interface not coming up after reboot, DEC3850

[stefan00]

Hi everyone,

I have a very strange issue with a recent Opnsense setup. In short:

The AX0 10G interface will not come up after a reboot, throwing an error. When I enter the interface settings and press "apply", the interface comes up.

Hardware Setup:

- Router: DEC3850, Opnsense 26.1.2_5
- Switch: Zyxel XGS2210-52HP
- Client: Mellanox CX311A @ Debian Host, Intel I5-7800 CPU, 8GTx4 link speed
- connected via 10G DAC cables

(For testing purposes, I eliminated the switch and plugged the client directly into the router. Same issue.)

(1) Connectivity

Connectivity / driver selection: I can only get the DEC3850 link 10G to the switch by selecting "10GBASE-KR" in Opnsense as speed/duplex model. Twinax DAC is not available.

In the system log right after boot, there is one obvious error:

Code Select Expand

2026-02-22T17:52:15 Error opnsense /usr/local/etc/rc.bootup: The command </sbin/ifconfig 'ax0' media '10GBase-KR'> returned exit code 1 and the output was "ifconfig: SIOCSIFMEDIA (media): Invalid argument"
(2) Performance once up

The issue might be linked. Even when up, I mostly get only about 1.5 Gbit/s throughput testing with iperf3 running ON the Opnsense box. It MAY spike up to 4 Gbit/s. It may even spike up to 7 Gbit/s.

This is vague since iperf3 is running on the router itself, but on other opnsense boxes I usually get 5-7 GBit/s even when running iperf3 on the router. Unfortunately, I did not have the chance of testing THROUGH the router due to the lack of addition 10G hardware on this specific location.

However, WAN speed also seems to be decreased to around 700Mbit (1G Cable downlink)

To sum it all up

This is strange. My primary suspects are:

(1) The DAC cable?

(2) Drivers in Opnsense?

It would be great if anyone has an idea of what to look at next. I never had such a strange problem with 10G networking. I am happy to provide more information.

Best & thanks,
Stefan


Attachments:

- syslog
- HWProbe at https://bsd-hardware.info/?probe=c67f01f83f

(edit: attached system.log)

[Monviech (Cedrik)]

Did you import an old configuration which may have different tunables set?

If yes try to reset the tunables to factory default via the red trash button. (System -> Settings -> Tunables)

[stefan00]

Hi Cedrik,

thank you for the fast reply.

Yes, I have removed my "personal" (old) tunings, but that might have been after the log dump I posted.

However, did not make a difference after reboot.

The system is not a new install. It runs since a couple years. Only change this weekend was installing a new switch on the location in order to upgrade to 10G. The DEC3850 itself has been running 10G previously fine in another location, but this has been some years ago - so many Opnsense / FreeBSD releases back in time.

[Monviech (Cedrik)]

Can you check whats the supported media list?

Code Select Expand

ifconfig -m ax0
If you find "media 10GBase-KR" can you try to set it manually and see if you get the same SIOCSIFMEDIA error as when booting?

Code Select Expand

ifconfig ax0 media 10GBase-KR

[stefan00]

ifconfig:

Code Select Expand

root@DEC3850:~ # ifconfig -m ax0
ax0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
        description: ax0hw (opt12)
        options=4e503bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
        capabilities=4f503bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWFILTER,VLAN_HWTSO,NETMAP,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
        ether f4:90:ea:00:64:37
        media: Ethernet 10GBase-KR (10GBase-SFI <full-duplex,rxpause,txpause>)
        status: active
        supported media:
                media autoselect
                media 100M-SGMII
                media 100baseTX
                media 1000Base-SGMII
                media 1000baseT
                media 1000baseSX
                media 1000baseLX
                media 1000baseCX
                media 1000Base-KX
                media 10GBase-SFI
                media 10Gbase-T
                media 10GBase-KR
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
root@DEC3850:~ # ifconfig ax0 media 10GBase-KR
root@DEC3850:~ #
no error ;-)

[Monviech (Cedrik)]

Well it seems like its a highly specific error then that fails to set this media type during boot only once.

I assume right after boot there is no carrier and no media type when checking ifconfig?