Exactly the same issue, we need this fixed ASAP (C9 V5 on 1.2.2 Build 20180423 rel.85787)

Same here with 1.2.2 Build 20180423 rel.85787

I have an Asus Tinker Board connected to the router by Ethernet. I need fixed IP, so I set an Address Reservation entry for it. But it is not issuing the IP address to the board.

In the Network Map it says 0 Wired Clients and I cannot access to the board. Wireless DHCP clients are OK.

I tried both to set a reserved IP from the IP address pool (currently 192.168.1.100-192.168.1.199) and also one outside of the Adress pool. It does not work either.

This is quite annoying for such a basic functionality. Due to the OS I need in the Tinker Board, to set fixed IP from the machine itself it's not trivial. I bought this router to substitute my ISP router to improve my network but now I'm thinking in returning it. It would be nice to have some feedback quick.

I just freshly bought the C9 and was fuming when I too ran into this issue.
This is one of the most-basic and critical features of a router and TPLink hasn't done anything about it since 2016 at least as this is not only existing since patch 1.2.3 (mine came with 1.2.1 and had the same problem even before patching).

For @ytakagi , @Saul_M, @gorigante  and everyone else finding this post: There is a user-side hotfix.

For me, it was the same issue mentioned here (https://community.tp-link.com/en/home/forum/topic/85863) and in some other topics and was solved by: Making sure all Address Reservation Descriptions do not contain spaces (or special characters besides at leats dash or lodash).

Once I removed all spaces form descriptions (all my reservaitons had descriptions) and replaced them with lodashes, DHCP worked as expected, including the reservations.

I hope that helps.

To TPLink: You're not reading these forums anyway do you? Seriously, I am on the verge of sending that piece of "made in china" back and stick to my old TP-Link router from back when TP-Link was "good".

• Your DHCP Server fails booting correctly and your logs are silent about it
• Since 2016 users have reported DHCP issues to none of which any TP-Link employee replied
• Users found a hotfix and you don't even bother to put that into your documentation
• This makes several "normal" consumer hardware useless too, not just Raspberry-Pies and whatnot. I like my NAS to have a static IP very much, thank you.

Thanks a lot Wortex17!

I just noticed that there is a new firmware 1.2.4 available, and installed on the router. I will check later if this issue is fixed and if not, try your workaround (althoug I would say I did not use spaces or weird characters on the Address reservation descriptions).

I completely agree with your appreciations regarding TPLink support. I finally kept this router but for sure I will bear this topic in mind whenever I buy my next network gear.

Hi guys,

I may have a solution.

I have reset my archer c9 to factory defaults by long pressing reset button and then reconfigure c9 manually.

I restored dhcp configuration including ip address reservation, it seems to work as I expect like before.

summary

before

• I have upgraded firmware to 1.2.3
• after that, c9 does not issue dhcp ip address when ip reservation entry exists
• I have down-graded firmware as before, the problem was not gone.

update

• I have reset c9 to factory defaults by long pressing reset button.
• I configured c9 as before( but minimum configuration, just for test )
• now c9 issues dhcp floating ip address and reserved ip address.
• After that, I upgraded firmware 1.2.4, it still works as my expectation.
• just in case, I have reset c9 to factory defaults with firmware 1.2.4
• I have configured c9 as before, it is working as before "tragedy".

P.S.

• I'm using "_" character in ip address reservation name entry. it works.
• configuration backup and restore may be same solution as above. ( but I don't try )

my guess

• firmware upgrade may collapse non volatile configuration area
• so, by downgrading firmware is not a solution for this problem.
• "reset" resets them cleanly so the problem may have gone.

This happened in this hour I cannot tell this is the solution,

but if you can, try once and write a report here.

Thank you.

I finally tested DHCP address reservation today and with 1.2.4 Build 20190403 rel.63869 firmware, it seems to be working OK so far. I am not using spaces on the description of the Address Reservation, as suggested, but I'd bet that I did not use them before neither, when it failed. So I guess this has been fixed on 1.2.4.

Wow.  Am I glad I found this thread.  I was about to trash this thing, wasted alot of time trying to figure this out.  Have to say, though, coming from the DD-WRT perspective, I'm fairly disappointed with this.  Just a thought...if descriptions don't allow spaces and mess up the dhcp process, then maybe, I don't know...just spit balling here, but what if you didn't allow saving those names on the front end in the GUI?  I mean, they actually do that on the DD-WRT interface.  Ever wonder why people seek out custom firmware?

Yeah wow this is pretty rediculous. I just spent the 2 days bashing my head against a wall trying to figure out the weird behaviour of this router all of a sudden. Turns out it was the spaces. Turn those spaces to underscores and all is right again in the world. Also to note I am on firmware: 1.2.4 Build 20190403 rel.63869. Hey TP-LINK ... maybe either fix this bug or put some warning somewhere in the GUI or make it reject spaces! What a waste of time.