Posted: Wed Jan 09, 2019 17:12 Post subject: Anyone happy with DD-WRT on Archer C8?
I have the c8 v2 and I have read nothing but complaints from ppl who have had DD-WRT installed for more than 1 day.
Are any of you guys happy with it?
I just bought a V2 with old OEM firmware, to use with 5g wifi and I would appreciate if someone can tell me they are happy with the performance.... especially regarding the disappearing 5g wifi.
Posted: Sat Jan 12, 2019 22:06 Post subject: Re: Anyone happy with DD-WRT on Archer C8?
Hi. I'm new to this forum and I'd like some help with DD-WRT for Archer C8 v1.
I've upgraded months ago from stock TP-Link firmware Build 20160517 Rel. 44603 to DD-WRT build v3.0-r37582 (11/03/18).
I was hoping to get a full set of services that I was assigning to my BananaPi server. I need ddns, dns, dhcp, openvpn, ssh, and ntp.
ohplease wrote:
Are any of you guys happy with it?
So I flashed dd-wrt to my main router. Oh boy, I'm not happy since then.
The main problem is that DD-WRT can't keep the router stable for long. I have to travel sometimes, and configured the router to provide the OpenVPN connection to my home. But it frequently crashes and leaves me without knowing what's going on with my network. I tried to set a scheduled reboot but, for it to be really efficient, I have to reboot the router every 3 hours. I don't know what happens, but suddenly the router crashes and most of the time it stays this way until I manually reboot it. It stops even routing traffic so, as it is my main router, all of my home services go down with it.
Recently, a new bug got in my way, and the router couldn't even get the DHCP IP from the WAN router. The solution was to force Static IP. There's a workaround to this already reported, but there are so many bugs... And I'm not used to the most advanced logs, so the "/tmp/var/log/messages" or syslog never gives me something useful to report here. All I know is that randomly or after a request (like web page browsing), all the services die (httpd, dnsmask, nas, wifi) and the router tries to re-exec them. Sometimes it succeeds (takes longer than manually rebooting), but mostly it doesn't, forcing me to manually reboot.
I've tried almost all the builds since 37582, none are really stable. The december/2018 builds seems to be more unstable than the others. Currently I'm using 38253.
Anyone here can guide me to point which build is the most stable? And which configurations should I avoid to maximize stability (like disabling nvram for dhcpd leases)?
Posted: Tue Jan 15, 2019 16:41 Post subject: Archer C8 v1 stability
I noticed that my Archer C8 v1 router was up for 3 days in a row, without manually rebooting! I'm using build 38253.
Today, I couldn't upgrade to 38302, always getting a "Failed" message on the webflash interface. Maybe 38302 is not good if you plan to flash DD-WRT from stock, it's just a warning.
Also, I noticed that even if the router was up for 3 days, a crash occurred hours after I manually rebooted on 12/january. The router could recover from the crash, but most of the processes did not re-exec, leaving me only with some basic functionality that I was not missing at this moment.
These ones did not come back:
/sbin/mstpd
lld2d br0
/tmp/openvpnserver
ttraff
resetbutton
wland
inadyn
cron
(ntp client)
(maybe more, couldn't determine all of them)
So, I'm supposing one of these are responsible for the instability I've being experiencing for a long time. I'll try to determine which one is the faulty process that makes the router crash randomly, and if I find something, I'll post here...
These ones I'm sure they re-exec-ed:
httpd
dnsmasq
syslogd (did not die)
(ssh server)
(dhcp server/client)
Posted: Wed Jan 16, 2019 20:43 Post subject: Memory leak on Archer C8 v1
Well, an update from the previous reply. I found that a unknown process in causing a memory leak on my Archer C8 v1. The "free memory" counter slowly decreases with time, and that's why I can keep the router running if I set it to reboot every 3 hours and, if I do not do so, it randomly crashes, as described.
I coudn't determine which process is causing the leak; my linux knowledge is not so advanced, I'm used to Ubuntu set of commands. Everything I try on DD-WRT gives a "command not found" or does not provide enough features to find the problem. I just need more time and search so I can find out what's going on.
ps and top commands do not help me here... ps does not give me memory use data, and top was supposed to do so, but when I type the S key to show memory use, it crashes: "top: no process info in /proc".
I tried to kill every process I could that has the command line listed on ps, but none of those kills reduced the memory usage. Maybe it's a kernel thing, I don't know.
If somebody can help me to identify the leaking process, I'd appreciate. Thank you.[/b]
I already tried to kill every process listed after PID 600 below, and some of the others that I don't know what they do.
Posted: Fri Mar 01, 2019 17:44 Post subject: Update on tests and stability
Well, I kept doing some tests, but I really couldn't find out exactly what is causing memory leak on DD-WRT Archer C8 v1. I can only guess it is a kernel process or module, because /proc/meminfo and top -n 1 -b do not report anything unusual related to a specific process...
I'll create another thread specific to report Archer C8 stability bugs.
I'm currently using Firmware: DD-WRT v3.0-r38937 std (02/23/19), and did a factory reset (same results as not doing factory reset), and most of my configurations are "default". I use dhcp+dnsmask, ddns, openvpn, wireless (2,4 only), syslogd+klogd, cron, port range forwarding.
Here are the problems I found:
- There is a huge memory leak related to network use. The more huge downloads I make, the leak will be proportional. A workaround for this was using a CRON job every 2 minutes that checks if MemAvailable is larger than 4MB; if not, reboots the router. If memory goes near ZERO, router will hang/crash, and only a power cut will get it back working again. The cron job is listed below (it's a one-liner):
Code:
*/2 * * * * root AVLB_RAM=$(cat /proc/meminfo | grep "MemAvailable" | awk '{print $2}'); logger -p user.warn "Available RAM: $AVLB_RAM kB; uptime: $(uptime)"; if [ $AVLB_RAM -le 4096 ]; then logger -p user.err "Available/Free RAM is too low. It's time to REBOOT..."; sleep 3; reboot; fi
- CRON won't start on reboot. It can start correctly and keep that way only when a firmware upgrade is done (without factory reset), but if I click "save" on CRON config page, it won't start at reboot anymore. I made a workaround using startup script so it checks /var/log/messages for my CRON jobs expected messages, and if they are not found after 5 minutes, then the script manually stops and starts CRON. No issues detected after CRON is restarted like this.
- CRON @reboot jobs won't work. Currently, I use startup script to handle those jobs. I had rare cases in previous builds when I could see @reboot jobs working, but I really couldn't figure out what I did, and how to keep them working.
- sleep does not seem to work on CRON. I let it there, but even using the full path it will still pass through without sleeping.
- LEDs: Wi-fi, LAN, and Internet leds do not work. If I enable USB support, then Internet LED goes live, but I suppose the function in not correct.
- Buttons: Reset and Wifi buttons do not work.
- The wifi range is slighly worse than stock firmware. Before, I could connect when still at street with a very low signal; now, I can't connect from there anymore. But when I open my metal gate, I can connect again. Not so much difference, though.
With all whose workarounds, I managed to keep my router running without forced power cuts. When I'm home, my network goes down at least 2 times a day for like 45 seconds, and that is the best the firmware can do at the moment. When I'm playing online, there are those nasty moments when I have to wait for the router to restart, so if you are a online gamer, DO NOT UPGRADE your Archer C8 v1 at this moment. If you download a lot of huge files, like ISOs, videos, console games, Netflix, etc, you'll also get a lot of reboots (every 30 min @25 MB/s).
If devs could work on this memory leak, I woudn't even complain about the other issues like CRON, LEDs or buttons, because I can get what I need from the router.
It is a great job. I still love DD-WRT even with those issues. But it can be a lot better! Thank you, devs.
hello people, first all, thanks for the great work and community
i am owner of a Archer C8 V1, running dd-wrt about 3 weeks and everything running smooth ( today i´ve upgrade to lastest build 10/04 39469) , only one question :
Has anyone managed to change cpu speed from 800 to 600 in C8? I do change, I record and reboot the router but then in status it always appears 800mhz
CPU ModelBroadcom BCM4708
CPU Cores2
CPU Features EDSP
CPU Clock800 MHz
Load Average
4%0.07, 0.05, 0.00
TemperaturesCPU 59.1 °C / WL0 40.0 °C / WL1 47.5 °C
Posted: Sun Apr 14, 2019 20:15 Post subject: Archer C8 V3 and CFE
Hi, i am planning to flash my current stock Archer C8 V3 with the latest dd-wrt image (yes i know it is not supported). But before i do that i would like to understand a few things, as this router does not have a web revert. From other post i read that the original firmware can be flashed from CFE and to boot to CFE i need serial access (not an issue). However the posts are not clear how to flash from CFE. There are multiply ways and commands, that i can figure out. But i was unable to figure out which image should i use. The downloadable files are bin files, while the examples are using trx files. Can someone explain the difference?
Also the V3 version has a recovery CFE GUI, anybody know how to boot the router to that prompt?
Thanks, i checked that and also the linked TP Link article. "Introduction: At rare occasions a router may become unresponsive during an upgrade process. The most common reason leading to this is the router losing power during the upgrading process. When becomes brick, the router’s Power and WPS LEDs are solid on. We provide an easy to follow method for customers to attempt to restore their router."
Based on this to get to the recovery, one has to 'brick' it first... Is there a better way? _________________ ---
Schnee
Posted: Mon Apr 15, 2019 20:46 Post subject: Re: Archer C8 V3 and CFE
schnee wrote:
Based on this to get to the recovery, one has to 'brick' it first... Is there a better way?
My bad...I thought it had a better description than that. There are normally a couple ways to get to the GUI recovery mode:
1. Hold down reset while powering on until the power light flashes, then access the default router IP address
2. After three failed boot attempts, such as powering off after ~10sec from power-up
Note: I haven't done this myself, but maybe another C8 owner here can confirm... _________________ #NAT/SFE/CTF: limited speed w/ DD#Repeater issues#DD-WRT info: FAQ, Builds, Types, Modes, Changes, Demo#
OPNsense x64 5050e ITX|DD: DIR-810L, 2*EA6900@1GHz, R6300v1, RT-N66U@663, WNDR4000@533, E1500@353,
WRT54G{Lv1.1,Sv6}@250|FreshTomato: F7D8302@532|OpenWRT: F9K1119v1, RT-ACRH13, R6220, WNDR3700v4
Posted: Tue Apr 23, 2019 1:40 Post subject: Re: Archer C8 V3 and CFE
schnee wrote:
Hi, i am planning to flash my current stock Archer C8 V3 with the latest dd-wrt image (yes i know it is not supported). But before i do that i would like to understand a few things, as this router does not have a web revert. From other post i read that the original firmware can be flashed from CFE and to boot to CFE i need serial access (not an issue). However the posts are not clear how to flash from CFE. There are multiply ways and commands, that i can figure out. But i was unable to figure out which image should i use. The downloadable files are bin files, while the examples are using trx files. Can someone explain the difference?
Also the V3 version has a recovery CFE GUI, anybody know how to boot the router to that prompt?
Thanks
You will need a dump of the SPI flash chip. Luckily, the flash chips on these are not NAND but serial. You will then need to desolder and flash it from the PCB.
I'm not sure how to do it through the serial console. I have accessed the C8's serial console, but in order to give you a proper dump, someone would have to tell me the correct memory addresses to dump, and that information is not available anywhere as far as I know with the C8 (though it is with the C9).
So again, easiest way to de-brick is an inexpensive CH341 flasher with a 16-pin adapter... You're talking about less than $10 in equipment. You will have to have some soldering skills though, but it's not that difficult.
Posted: Tue Apr 23, 2019 20:08 Post subject: Re: Archer C8 V3 and CFE
dribgnikcom wrote:
You will need a dump of the SPI flash chip. Luckily, the flash chips on these are not NAND but serial. You will then need to desolder and flash it from the PCB.
I'm not sure how to do it through the serial console. I have accessed the C8's serial console, but in order to give you a proper dump, someone would have to tell me the correct memory addresses to dump, and that information is not available anywhere as far as I know with the C8 (though it is with the C9).
So again, easiest way to de-brick is an inexpensive CH341 flasher with a 16-pin adapter... You're talking about less than $10 in equipment. You will have to have some soldering skills though, but it's not that difficult.
I am looking for a solution to flash the router from teh CFE promnt (no desoldering) or a way to boot to the recovery GUI which is implemented in V3.
Anyway i already tried to flash dd-wrt on the router and failed even with several different methods (including modifying the fimrware file to have v3 as supported). _________________ ---
Schnee
I have Archer C8 V1 and firmware DD-WRT v3.0-r40260 std (07/09/19), and experience numerous problems. The most pressing one is with Samba. I use an external USB 3.1 1TB hard drive that worked very well with stock firmware. Now I can access the NTFS volume on it but cannot write anything there from my Windows 10 computers. The error message says that "Access is denied" and "You need to get a permission".
I wanted to use DD-WRT to make my router's Samba server more secure, and instead lost Samba completely. I hope somebody will either help me make the NTFS volume writable or help me revert to OEM firmware. I am able to telnet into the router, and just need the right set of commands. Thanks in advance
Posted: Sat Jul 13, 2019 13:53 Post subject: Problem solved
I was able to revert to the stock firmware using the procedure described at https://crosp.net/blog/hardware/unbrick-tp-link-wifi-router-wr841nd-with-tftp-wireshark/. The IP from the blog (192.168.0.66) showed up for Archer C8 as well, and the expected name was ArcherC8v1_tp_recovery.bin. It was not at all difficult, and it is a crying shame that TP-Link never documented it, because it likely works for many their older routers.
