Since there are a lot of different switches based on Realtek chipset, with in general little support, i tried to consolodate the firmware versions below. Double check before installing, updating the firmware is at your own risk.
SL-SWTG124AS:1.9 Version Download
SL-SWTGW215AS:1.9 Version Download
SL-SWTGW218AS:1.9 Version Download
SL-SWTGW2C8F:F11124 Version Download
SL-AFGW-242S-400:6.7 Version Download
SKS3200M-4GPY2XF 1.91 Version Download
SKS3200M-8GPY1XF 1.91 Version Download
SKS3200M-5GPY1XF 1.91 Version Download