Cannot open 1701 port on Archer C80
This Article Applies to: Archer C80_V1 Issue Description/Phenomenon: 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 that 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.
Available Solutions: Step 1 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. Step 2 If you still fail to open the 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:
Related Articles: How to open a range of ports on Archer C80 Port forwarding: how to set up virtual server on TP-Link wireless router? Why port forwarding feature is not working on my router?
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Re:[Solution] Cannot open 1701 port on Archer C80
@Kevin_Z Thank you for your effort. It seems impossible to update from version 1.10.0 Build 210716 rel.51301n(4555).
Could it be that the router is seeing this firmware as a "downgrade"?
Not being able to use port 1701 is a big issue for me. Could you please have a look at it?
Re:[Solution] Cannot open 1701 port on Archer C80
Thank you for working on the new beta version. I also want to open port 1701 for L2TP VPN server on my synology. However, this is not possible.
My setup:
ISP router LAN port connected to TP LINK WAN port.
TP LINK LAN port connect to SYNOLOGY NAS.
TP LINK Router connected to the internet by PPPoE session.
This is the error message while trying to forward my port:
