Silicom PE325G2I71-XR-CX dual-port 25GbE NICs pulled from decommissioned Citrix NetScaler SDX-15000 appliances. 8 available, open to reasonable bulk offers.
Silicom's OEM build of the Intel XXV710-DA2. Same chip, same driver, same performance. The -CX suffix just means it was built for Cisco/Citrix and makes no difference in any standard server.
Two SFP28 ports, PCIe 3.0 x8, low profile. Runs 25GbE natively or drops back to 10GbE with standard SFP+ modules. SR-IOV supported up to 128 VFs.
Linux i40e driver has been in-kernel since 3.14, so it's plug-and-play on any modern distro: Ubuntu, Debian, Rocky/RHEL, Proxmox, TrueNAS. Windows Server and ESXi 6.5+ work with Intel's standard LAN driver. No SFP whitelist enforcement.
Low-profile bracket installed, full-height not included. Generic XXV710 brackets off fit fine if you need one.
Also listed as: Intel XXV710-DA2 / XXV710DA2BLK, Dell HN7J7 / 00M95