Solution Cannot open 1701 port on Archer C80
This Article Applies to:
There are cases that customers want to access a local L2TP/IPSec VPN server from an outside network, thus they will be required to open some specific ports on the gateway router, such as port 500, 4500, and 1701.
Typical network layout would be as follows:
However, customers will find they cannot open port 1701 on the Archer C80, it reports an error "Conflicting with existing port: 1701. To avoid conflict, please enter another value.". This is because the 1701 port is reserved for the L2TP WAN connection on the Archer C80 with the previous firmware, and you cannot open it for another server.
Update and install the latest firmware for the Archer C80, which is Archer C80_V1_1.11.30 Build 220624, then try to open port 1701 for the local L2TP/IPSec VPN server on the router.
If you still fail to open port 1701 on the C80, please disable the IPSec Passthrough on the router. You can find it under the Advanced > Security > ALG page as follows:
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