Address reservation BUG on X20?

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Address reservation BUG on X20?

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Address reservation BUG on X20?
Address reservation BUG on X20?
2022-07-16 09:57:24 - last edited 2022-09-08 01:55:20
Tags: #Port Forwarding #address reservation
Model: Deco X20  
Hardware Version: V2
Firmware Version: 1.1.3 Build 20211103 Rel. 32888

Hello,

 

I found strange behavior with address reservation on TP Link Deco X20.

 

When I add a client f.e. 192.168.2.x to address reservation and later return to address reservation, the address is changed to 192.168.0.x

 

This issue only occurs when using one of the following internal networks:

 

192.168.1.x

192.168.2.x

192.168.3.x

192.168.4.x

 

A factory reset did not resolve the issue. 

 

I have reported this issue before via email and shared log files, but did not receive a response with solution. Initially being informed that this was caused because my internet router was not running in bridge mode. Now it runs in bridge mode, but same issue occurs.

 

My setup:

WAN: Bridge Mode

LAN IP: 192.168.2.254/24

 

DHCP Server:

Start IP: 192.168.2.50

End IP: 192.168.2.250

 

Below screen shows when I add a client:

 

 

When I leave menu and go back, the address changed.

 

Hopefully there is a solution for this issue.

 

Thanks!

 

 

 

 

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#1
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1 Accepted Solution
Re:Address reservation BUG on X20?-Solution
2022-07-18 00:49:27 - last edited 2022-07-20 08:46:29

  @frederikk @Peterdu 

Thanks for the feedback.

We have updated a beta firmware here that would help with the current issue:

https://community.tp-link.com/en/home/forum/topic/567404

Please install this firmware first and it is highly appreciated if you could let me know whether it worked or not.

 

@Peterdu  By the way, based on our test, the problematic LAN IP range is from 192.168.0.1-192.168.3.254.

But based on your description, it was in another range 192.168.1.1-192.168.4.254.

So I wonder if your LAN IP is 192.168.0.1/255.255.255.0, will you also have the current issue?

Thank you very much.

Best regards.

 

 

Recommended Solution
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#9
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9 Reply
Re:Address reservation BUG on X20?
2022-07-16 13:23:40

  @Peterdu 

 

Peterdu wrote

 

My setup:

WAN: Bridge Mode

LAN IP: 192.168.2.254/24

 

DHCP Server:

Start IP: 192.168.2.50

End IP: 192.168.2.250

 

 

What is your Main Deco WAN IP and WAN DNS servers IPs? See https://www.tp-link.com/us/support/faq/1855/ if you need help in finding where these IP addresses are.

 

Also, while we are on it, have you specified LAN DNS IP addresses or left them empty, which is by default.

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#2
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Re:Address reservation BUG on X20?
2022-07-16 13:46:02

  @Alexandre. 

 

WAN: 217.63.5.7

DNS 1: 84.116.46.21

DNS 2: 84.116.46.20

 

I haven't specified a LAN dns server.

 

Thx

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#3
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Re:Address reservation BUG on X20?
2022-07-16 13:52:05

  @Peterdu 

 

There is known case when WAN IP or WAN DNS IP is from the same IP segment as LAN. I thought it might be the case here, but it is not.

 

If you try different LAN IP range, for example 172.16.0.*, does problem also exits?

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#4
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Re:Address reservation BUG on X20?
2022-07-16 14:00:59

  @Alexandre. 

 

It only occurs with the following ranges:

 

192.168.1.x/24 until 192.168.4.x/24.

 

I have tested other ranges and works fine.

 

Unfortunately changing internal LAN is not an option for me.

 

I don't understand how it's even possible that TPLINK shows an IP that's outside range of configured network. 

 

Manually adding reservation 192.168.0.x is not possible as expected.

 

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#5
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Re:Address reservation BUG on X20?
2022-07-17 10:15:36

  @Alexandre. 

 

I'm even able to replicate these issues with a clean standalone install without any wires connected. 

 

- Factory Reset

- No WAN connected

- No LAN connected

- Only my mobile connected to WIFI 

 

See here result, same issue: https://youtube.com/shorts/9RXxm2n0_B8?feature=share

 

I don't have any other explanation that this is a BUG in TP-Link software. If someone has any other explanation, let me know. 

 

So the issue persist that after saving 192.168.2x address it is suddenly changed to 192.168.0.x.

 

Another thing I tried is creating a larger network that includes 192.168.0.x - 192.168.2.0 by changing the subnet mask to 255.255.252.0. And in DHCP only configure range 192.168.2.50 - 192.168.2.250. 

 

Although clients ignore the reservation, it is interesting to see that IP addresses don't change in a wrong IP anymore. 

 

Starting from 192.168.5.x there are no issues. 

 

 

 

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#6
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Re:Address reservation BUG on X20?
2022-07-17 21:38:41

  @Peterdu 

 

Hi,

 

I don't understand your network,

 

 

LAN IP: 192.168.2.254/24

what is this network ? I can understand 192.168.2.0/24 but not this one.

 

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#7
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Re:Address reservation BUG on X20?
2022-07-17 21:45:48

  @Peterdu 

 

By the way :

 

https://community.tp-link.com/en/home/forum/topic/567404

 

similar issue. 

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#8
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Re:Address reservation BUG on X20?-Solution
2022-07-18 00:49:27 - last edited 2022-07-20 08:46:29

  @frederikk @Peterdu 

Thanks for the feedback.

We have updated a beta firmware here that would help with the current issue:

https://community.tp-link.com/en/home/forum/topic/567404

Please install this firmware first and it is highly appreciated if you could let me know whether it worked or not.

 

@Peterdu  By the way, based on our test, the problematic LAN IP range is from 192.168.0.1-192.168.3.254.

But based on your description, it was in another range 192.168.1.1-192.168.4.254.

So I wonder if your LAN IP is 192.168.0.1/255.255.255.0, will you also have the current issue?

Thank you very much.

Best regards.

 

 

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  0  
#9
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Re:Address reservation BUG on X20?
2022-07-18 15:58:29

  @David-TP 

 

Hello,

 

Thanks for your help. 

 

The new firmware resolved the issue.

 

I could be wrong about the range as I was testing this some time ago when I submitted a support ticket back in February.

 

Thanks again.

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#10
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Helpful: 2

Views: 1125

Replies: 9

Tags

Port Forwarding
address reservation
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