Solution 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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Hello
HW:
Firmware Version:
1.11.30 Build 220624 Rel.50807n(4555)
Hardware Version:
Archer C80 1.0
I am having a similar issue after updating to C80_V1_1.11.30 Build 220624; this worked while I was on the beta firmware which was posted here a while ago (post was edited since then) -- I can't downgrade either :-(
The network layout is very simple :
Router connects to the internet through PPPOE and my Synology NAS (running L2TP VPN) is connected to router (wired). I have a few other devices on my network (IoT devices, Tv etc)
I am able to connect to the VPN server from inside the network (by using the local ip -- 192.168.0.105) but I am not able to do that from outside the network even though the pass-through option is enabled and ports are forwarded.
Just to reiterate, this worked on the beta fw that was posted here (c80v1-up-noboot_2021-02-19_10.17.18.zip)
I've tried with no other devices/cables connected, except WAN and Synology after multiple factory resets but to no avail.
DMZ doesn't work either
Here's my router config:
Thank you
-Alex
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Hi Alex, thank you very much for the detailed information regarding the port forwarding settings on the C80.
To assist and figure it out efficiently, I've forwarded your case to the TP-Link support engineers who will contact you with your registered email address later. Please pay attention to your email box for follow-up.
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it's happen on Archer C80 V2.20 right now.
i have try to disable alg IPsec Passthrough, then turn on trigger port forword to my NAS - VPN Server, however it still shows the conflict message.
the firmware version: 1.10.3 Build 220323 Rel.71165n(5457), the env with wan type is PPPoE
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That's not good.
To assist and figure it out efficiently, I will forward your case to the TP-Link support engineers who will contact you with your registered email address later. Please pay attention to your email box for follow-up. Thank you.
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yap, they contacted me 2 weeks ago, and promised to release a firmware before the end of 2022. (they didn't make it happen)
they released a beta firmware 2 days ago, and i have tried those steps from this post.
unfortunately it doesn't work at all, only the port forward UI is unblock. (feedback reported)
i ask the status via email everyday and get no response or slow response (like 3-7 days).
i have no idea how to reach with your services.
The supported engineer is keep asking how i setup vpn server on c80??? (at least 3 times, it pxxxxx me off)
Don't you guys know there isn't vpn application on basic router??? (don't ask the knowledge of your product again and again)
i'm trying to provide all my captures about my testing environment, and it doesn't help.
i have no idea if they read and understand my network topology? so they kept asking weird questions.
also, they are asking my provided information and environment repeatly (it pxxxxx me off again and again)
Finally, i got the response that you are "such" good, why don't you test by yourself the port funtion.
WAN port -1701 doesn't block, doesn't mean the forward function is work.
that's the my sample environment
vpn client------------WAN IP (UDP 500, 1701,4500)-------> Access (VPN Server)
before
vpn client------------WAN IP (UDP 500,4500 ,opps 1701 port was blocked)-------> Fail
the testing result with beta version (before the 1701 was blocked, and the beta version is open)
vpn client------------WAN IP (UDP 500, 1701,4500)-------> Fail
vpn client------------LAN Server (VPN Server)-------> Pass
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Sorry to hear you’re experiencing issues with the new firmware, and the interaction with our support agent was anything less than satisfactory. We would appreciate another opportunity to follow up and address your concerns.
We’d love to follow up with you and solve the issue via email, and your case would be escalated to the engineering directly for further analysis. Please check your email box and keep working with our engineers.
Thank you for your understanding and cooperation.
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It seems the support engineer has helped confirm the issue, please wait for the new official firmware to be released for your router. Thank you.
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@amberneedyou note that this thread is for HW version V1.
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