Install SONiC on Dell S5212F-ON: Budget 25GbE/100GbE

The flood of used Dell -ON suffix switches on the second-hand market made 25GbE and 100GbE affordable for homelabs and small businesses, but many arrived locked to Dell OS10, which needs an expensive license and can reboot every 72 hours without one. This hands-on guide shows how to escape that trap: update the switch firmware, boot into ONIE, install the open-source community SONiC image from a USB stick, and bring the switch up as a fully open network OS. Written from real experience with the Dell S5212F-ON, it covers the gotchas that the quick-start docs do not mention.

Background: Why an Alternative OS

These switches were cheap partly because they only worked with Dell OS10 (which is expensive), and OS10 would reboot the switch every 72 hours without a valid license. Non-Dell operating systems advanced quickly because of this — SONiC is fully open source and production-hardened in hyperscale data centers, making it the natural choice.

Update the Firmware First

Use a serial console at 115200 baud. Update the Dell platform firmware before installing anything — the ONIE firmware was so old on some units that the update had to be applied twice, updating BMC, BIOS and FPGA firmware in different steps. Default credentials are admin/admin for the switch OS and linuxadmin/linuxadmin for the Linux shell user.

Install SONiC via ONIE

Download the Broadcom SONiC BIN file, copy it to a USB drive, and boot the switch into ONIE. From the ONIE menu choose Uninstall OS first (to remove OS10), reboot, then select Install OS:

GNU GRUB version 2.02~beta2+e4a1fe391
+----------------------------------------------------------------------------+
|*ONIE: Install OS
| ONIE: Rescue
| ONIE: Uninstall OS
| ONIE: Update ONIE
+----------------------------------------------------------------------------+

mkdir /mnt/media
mount /dev/sdb1 /mnt/media
onie-os-install /mnt/media/sonic-broadcom-filename.bin

The installation takes a while; then log in with the default SONiC credentials admin/YourPaSsWoRd.

Configuring the Switch

SONiC comes up in router mode by default, with every interface getting an IP. On some builds even show commands require sudo, which differs from the documentation — remember to prefix with sudo when you hit permission errors reading the EEPROM:

admin@sonic:~$ show interface status

If you get a PermissionError reading /sys/class/i2c-adapter/i2c-0/0-0050/eeprom, re-run the command with sudo. From there, configure interfaces, VLANs and routing with the standard SONiC config commands.

Hardware Notes

The S5212F-ON is loud — fans ramp to over 9000 rpm when a fan is removed. If you replace fans with Noctua 40mm units, expect the switch to complain and run the remaining fans at high speed; monitor temperatures carefully after any fan swap.

Related open-networking articles: the SONiC troubleshooting guide, ONIE and Onyx MLNX-OS installation, and getting started with Mellanox switches.

原文链接：https://forum.level1techs.com/t/dell-s5212f-on-alternative-os-sonic-setup-guide-25gbe-100gbe-on-a-budget/198643