Cannot open 1701 port on Archer C80

Cannot open 1701 port on Archer C80
Cannot open 1701 port on Archer C80
2021-07-21 02:21:38 - last edited 2022-07-22 09:43:45
Model: Archer C80  
Hardware Version: V1
Firmware Version:
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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#1
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21 Reply
Re:[Solution] Cannot open 1701 port on Archer C80
2021-07-22 18:17:29 - last edited 2021-07-22 20:30:52

To others: Please note you will lose all your settings when you flash this (IP, LAN, WAN, logins, static IP etc.) it will act as a new setup and have BETA FIRMWARE all across the UI background.

I was able to setup the port 1701 to forward in the UI and am testing now if it fixes our issue and is passing through.

 

*This has not solved the problem in my enviornment, however it is possible this is a PPTP issue on 1723 and not related to 1701 on this firmware.

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#2
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Re:[Solution] Cannot open 1701 port on Archer C80
2021-08-03 06:37:28
Thanks for the clarification.
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#3
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Re:[Solution] Cannot open 1701 port on Archer C80
2021-09-27 13:58:19

@Kevin_Z This is such a great asset that you are giving and you part with it for nothing. I love seeing web journal that comprehend the benefit of giving a quality asset to free. 

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#4
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Re:[Solution] Cannot open 1701 port on Archer C80
2021-10-15 18:59:45

@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?

 

 

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#5
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Re:[Solution] Cannot open 1701 port on Archer C80
2021-10-18 02:28:34

@Grandshock 

 

The beta firmware we provided here is an older and lower version for the Archer C80, you cannot install it on the latest 1.10.0 Build 210716 rel.51301n(4555).

 

Can you please confirm the issue you are experiencing now? Do you also want to open port 1701 for the L2TP VPN Server but cannot? What is the error message? Please provide the detailed network layout, then we will confirm.

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#6
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Re:[Solution] Cannot open 1701 port on Archer C80
2021-10-23 09:42:33

@Kevin_Z 

Hi , I tried open port 1701 now, at 1.10.0 Build 210716 Rel.51301n(4555) FW, but without succes. I tried disable IPsec, L2TP in Security/ALG

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#7
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Re:[Solution] Cannot open 1701 port on Archer C80
2021-10-26 05:47:25

@Pajik77 

 

Hello, thanks for reporting the same issue to the community. We will provide an updated beta firmware soon, please kindly wait.

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Re:[Solution] Cannot open 1701 port on Archer C80
2021-10-26 06:05:45 - last edited 2021-10-26 06:07:57

@Kevin_Z 

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:

 

 

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#9
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Re:[Solution] Cannot open 1701 port on Archer C80
2021-11-17 07:29:52

@Kevin_Z Good Day

 

Is there any update regarding working firmware. Really need to get port 1701 open

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#10
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Re:[Solution] Cannot open 1701 port on Archer C80
2021-11-17 08:09:35

@AlonN 

The engineers are still working on it. We will update here once it is available.smiley

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