Dear @acesxi,
acesxi wrote
Hello, how do I set the TLR605 to have 1000M (1Gbe) LAN link speed? I have the setup below:
WAN port > CAT6 cable > ISP router = link is 1000M via AUTO nego
WAN2/LAN1 port > CAT6 cable > ISP2 router = link is 1000M via AUTO nego
dedicated LAN port > CAT6 cable > TP LINK DECO M5 router LAN = link is 100M via AUTO nego
There is no option on port config to manually set to 1000M, is there a WORKAROUND for this??
Go to Network > Switch > Port Config to manually set the speed and duplex mode for the desired port.

It is recommended to configure both devices of a link to work in Auto-Negotiation mode or manually configure them to work in the same speed and duplex mode.
As far as I know, TP-Link devices including Deco M5 and R605 router work in Auto-Negotiation mode by default. In normal cases, they will advertise their speed and duplex abilities to each other, and negotiate the optimal speed and duplex mode. If not, it could be the cable issue, you may change cable for checking.
If the local device works in Auto mode while the peer device does not, the local device will automatically detect and match the speed with the peer device. The local device will work in half-duplex mode, no matter what duplex mode the peer device is in.