Recommendation: Keep a backup of the original C1 firmware before attempting OpenWrt.
Tools:
# Split CFE from firmware
dd if=original.bin of=cfe.bin bs=1k count=64
dd if=original.bin of=linux.bin bs=1k skip=64
If your internet is working perfectly, check the release notes of the new firmware. If the update only fixes "minor bugs," you might choose to skip it. However, if the update addresses security fixes, it is highly recommended to proceed. firmware d-link dsl-2750u h w c1
Even with the correct firmware, you might encounter issues. Here are solutions:
OpenWrt provides a modern Linux kernel (5.10+) with full security updates, CAKE QoS, SQM, IPv6, and WireGuard. Recommendation: Keep a backup of the original C1
Using binwalk -Me:
binwalk -Me DSL-2750U_C1_FW_IN_1.10.bin
Output:
Based on OpenWrt but with a proprietary web UI. Includes ADSL driver support that official OpenWrt sometimes lacks.