Chaos Calmer (15.05.1+) with WPA2 KRACK vulnerability fixes built from 20171103 github sources:
, sysupgrade tested on hardware v1.3
Flash from OEM firmware
EASIEST WAY TO REFLASH STRAIGHT OUT OF BOX:
Download the OpenWrt factory firmware for this router above and rename it from “openwrt-ar71xx-generic-tl-wdr3500-v1-squashfs-factory.bin” to “wdr3500v1_tp_recovery.bin”
Plug the router directly into your ethernet and turn the router on. (You may have to turn off wifi (easy) or change the order of devices your computer connects to network (google it) so the ethernet device takes precedence.
Open Browser and navigate to http://192.168.0.1/, login= admin password= password. (in my case, it was password=admin)
On the left, navigate to SYSTEM TOOLS
Click on FIRMWARE UPGRADE
Point the router to the file “wdr3500v1_tp_recovery.bin” you renamed in step 1.
Click UPGRADE…..that's it.
DO NOT UNPLUG OR POWER OFF YOUR ROUTER DURING UPGRADE or you will likely have a Brick
login to 192.168.1.1 to confirm firmware upgrade.
it may be possible to do this firmware upgrade wirelessly, however it is not recommended. Use Ethernet to reflash firmware whenever possible.