New Xiaomi router AC2100

Thank you very much, after new year I'll dig into this and get the information. Maybe in the weekend!

Hi there,

I've been following the post for a few months now.
I bought the router because of the good Wireless Signal.

In the last few posts, the poor Signal compared to the stock firmware was mentioned.

Should I stay on the stock?
What are the chances that range will get better with new images?

With the stock firmware, I only have concerns about security and sniffing from China. What do you think about that?

Hi @Blum0r
I am not using 5 GHz Wifi - but with regards to all other functionalities OpenWRT is a huge improvement compared to the stock firmware.

  • The UI comes with the support of multiple languages
  • You have the possibility for addons (like Ad-Blocker)
  • You have much more adjustment possibilities
  • And it is certainly safer, because it is open source

For me it is perfect. But in case you need to use 5 GHz then you need to be aware that for now the performace is weaker. I am not able to assess if it will be equal or better in performance one day with regards to this feature.
2.4 GHz WiFi works perfectly fine (huge range, stable and low latency).

Hi,

5 Ghz is maybe weaker on OpenWRT than stock, but it is perfectly usable:

I have an archer C7 v2 + 1 Redmi AC2100 (white) + 1 Mi AC2100 (black), all running OpenWRT 19.7.5

  • 5 Ghz on both AC1200 is better than Archer C7 (same range but more stable).
  • 2.4 Ghz is weak on Mi AC2100 (black)
  • 2.4 Ghz is really STRONG on Redmi AC2100: very good coverage/range.
  • 2.4 Ghz on archer C7 is between the 2 AC2100.

All devices are used on AP mode and broadcasting the same SSID on the same network.
Clients are roaming from an AP to another without any problem : no noticeable differences.

I don't think that 5Ghz is weak in Openwrt. Is just a bit stronger in stock and it's the difference between being usable in my bedroom or not. I would use Openwrt if it wasn't for that, it's just that much better.

Hi, finally had the time to check and it's not using it and it's not an option, the width is 80MHz. And I guess some channels or strength used in stock are not exactly "legal" in every country.

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You recommend openwrt or padavan ?

There are several versions from Padavan I have tried.
Among Padavan I prefer this version, as it is the baseline: https://github.com/hanwckf/rt-n56u

Comparing OpenWRT and Padavan both have advantages and disadvantages.
As mentioned before I can't judge about 5 GHz, because I am not using it.

But with regards to all the other features and with regards to my use case (usage in repeater mode) it looks from my perspective like this:

OpenWRT:

  • Stable kernel without bugs [+]
  • Newer kernel, which is more efficient and offers higher processing speed. This is important in case you have high CPU loads, and in case you need to overclock the CPU to 1100 MHz [++]
  • High flexibility and extendability. Additional SW packages are provided in Luci [++]
  • High RAM usage (appr. 50% in base setup) [-]

Padavan:

  • System log shows kernel bug (in repeater mode), but it does not affect functionality [-]
  • Old kernel [-]
  • 2,4 GHz WiFi has even lower latency and jitter, which is very important for me due to VoIP usage [++]
  • RAM usage is appr. 20% [+]

I have to use VoIP over a VPN network and bad network quality, therefore I am using Padavan, because the voice quality due to less jitter in 2,4 GHz WiFi is better.
But I keep trying OpenWRT (scp07 and snapshot builds) to see the improvements with regards to my needs.

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Dear @RVB
thanks for checking!

Thanks for the info, If you set OpenWrt as your daily driver, please let know us.

Dear @cess94xp
You made me laugh :smile:
I am unimportant with regards to this.
Everybody needs to decide upon his needs what he wants to use.
Actually I am with Padavan because of lower jitter (important for VoIP quality), but in case my use-case changes, I would go back to OpenWRT, because it is much more flexible and modern, due to the more recent kernel. And also if I see one day that OpenWRT is better in regards to jitter.
Did you test both, and what are your experiences?

I tried the compiled builds from scp07 and well, its ok but in 5ghz if I go to my bedroom, one floor up, I have packages lost, I changed to recent snapshot this problem is gone and actually is ok but yeah, jitter is still a bit high and latency too, and I dont have full speed from ISP in WiFi, I have 300mbps download link and the max I get in my phone is 250mbps, sometimes less of that, in 2,4ghz is ok and yeah a little bit high jitter too.

In Padavan from hanwckf there are some kernel bugs and is really outdated but I have very good speeds in WiFi in both bands, I have the full download speed from my ISP in 5Ghz, latency is good and jitter is good too, my problem is if I move some meters with 5Ghz conection Im having packet lost problem until gets stabilizie but if I move again the same thing happens, that piss me off sometimes, I go to my bedrom to answer a private videocall but I have to wait the "estabilization" or change to 2,4ghz WiFi.

Im always using as AP in both firmwares.

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I managed to solve my "bricked even with breed"-problem. (see reply)

To do this, I proceeded as follows:

  1. Download stock boot-loader from https://forum.openwrt.org/t/new-xiaomi-router-ac2100/48101/1012
  2. Download MiWifi Repair Tool and Stock-Rom for AC2100 from http://www1.miwifi.com/miwifi_download.html
    • To solve the download-error problem you have to replace http://bigota.miwifi.com in the url with http://cdn.cnbj1.fds.api.mi-img.com. So for example the download-url for the repair tool is now http://cdn.cnbj1.fds.api.mi-img.com/xiaoqiang/tools/MIWIFIRepairTool.x86.zip
  3. boot to breed
    • plug router out
    • hold reset
    • plug router in - wait until led flashes orange
    • plug pc lan cable in one of the lan ports (not wan!)
    • set pc lan-ip manually to a ip in the range 192.168.1.0/24
    • open 192.168.1.1 in browser or with telnet
  4. flash downloaded stock bootloader with breed (from browser or telnet)
  5. reboot router
  6. boot to recovery mode (same procedure like boot to breed)
  7. set pc lan-ip to 192.168.31.5/24 with 192.168.31.1 as gateway
  8. connect pc lan-cable with wan(!)-port of the router
  9. Flash stock-rom
    • Open MiWifi-Repair Tool
    • Choose the downloaded stock rom
    • go further by clicking button in lower right corner
    • choose ethernet-adapter
    • click lower right button (maybe more times)
    • MiWifi repair tool may close but in the end the router should reboot by itself
  10. Done! - router is on stock rom again

After it i tried to flash openwrt like i did last time (the PPPoE-exploit) but i didn't managed to get a connection to netcat-session. So i tried the other method by activating ssh with special urls and was successful with it.

So maybe this could help someone in the same situation like me.

Dear @Sylvan
I am glad that the bootloader I had found in the Chinese forum has helped you to unbrick your device, so that you can use it again :+1:
By the way, did you know that some production lots of the RM2100 (white AC2100 with 6 visible antennas) were delivered with chips that have bad blocks?
You can read about this in the same Chinese forum (just use Google translate for it).
This would explain why you had been facing those problems with BREED.
You should keep a backup copy of the bootloader for the case that they take it down from the link I had posted.

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Yepp - just forget to say thank you to you for that!
The router was in the cupboard here and I actually wanted to get rid of it a long time ago. But then I saw your post and thought: Ok - it still has one more try.

Urgh - How does this manifest itself? Does it only cause problems when flashing or also during regular use?
Up to now (since yesterday) it seems to have been running quite stably since yesterday.

Sure - that was the first thing I did. :wink:

Dear @Sylvan
you are welcome!

I have learned so much by the people in this forum ... and I was always reading without joining this forum ... then recently I thought to give back a bit ... and joined ... and wrote a bit.
And I am really glad that I could benefit you.

With regards to the bad blocks I have read that it can be identified in the boot log. And that it does not affect the performance. But as my router is fine I didn't read into the details.
Just check the boot log ... if you don't see any fault message ... you don't need to care about what I wrote :slight_smile:

AFAIK, the ones with Toshiba NAND chip almost always have bad blocks, the ones with ESMT chip does not have bad blocks problem.

Hi @cess94xp, which snapshot do you tested? I don't care about jitter.
Do you know if can be installed over scp07 19.7.5 with sysupgrade.bin via web interface?

Thanks!

Do you know if the chip can be identified without open the router?

Thanks!

If you use Breed, it's listed on the main page, if not, then this entry from xiaomi R3P wiki page might interest you: https://openwrt.org/toh/xiaomi/xiaomi_r3p_pro#nand_chip_warning

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