Unable to flash TP-Link WR850N (tikona) ver2.0

[kanakshilledar]

Hello!
I am new to openwrt project. I tried building the openwrt image myself for the router TP-Link WR850N using the build steps provided as there was already an image available. This router was provided by Tikona broadband providers.
I dont get any firmware upgrade option in the router settings page. I am unable to access the uboot console it directly boots up and gives a shell with the following prompt

TL-WR850N login:

I tried admin:admin but it didnt work.
Normal boot log:

tl-wr850n normal boot log - Pastebin.com

I have setup a TFTP server on my laptop with the IP 192.168.0.66 and it also have the file named tp_recovery.bin it is this openwrt-ramips-mt76x8-tplink_tl-wr850n-v2-squashfs-tftp-recovery.bin file.

Logs after pressing RESET button and powering on

tl-wr850n reset-switch boot log - Pastebin.com

I dont know how to proceed further. Also if you need anymore logs or info please let me know.

Thanks and Regards!

[Wallbanger]

Hi...according to https://portforward.com/tp-link/passwords/ credentials are
blank:admin
at least for v3

HTH

[kanakshilledar]

This is what the router login page looks like in the firmware upgrade section.

I have no option to add any ota upgrade. I think firmware upgrade is locked in this router. How shall I disable it?

Also I am able to login to the router management console but in the serial output there is another login prompt which asks for username and password. I tried admin:admin and no success.

Thanks and Regards!

[kanakshilledar]

This is the login page in serial output.

[frollic]

@kanakshilledar

Logs after pressing RESET button and powering on
I dont know how to proceed further

the snippet from the log you posted, tells you everything you need to know

TFTP from server 192.168.0.66; our IP address is 192.168.0.2
 
Filename 'tp_recovery.bin'.

Setting up a TFTP server for TFTP Recovery/Install

[kanakshilledar]

I have the TFTP server up and running I am using xinetd for setting up tftp server.
After the Filename tp_recovery.bin it says Retry count exceeded and proceeds with booting the kernel image. I doesnt boot the TFTP recovery.
I have tested the TFTP server and it is working fine.
Can you please tell how can I fix this? I even tried the official image and it also giving the same output.

Thanks and Regards!

[frollic]

@kanakshilledar

I have the TFTP server up and running I am using xinetd for setting up tftp server.
After the Filename tp_recovery.bin it says Retry count exceeded and proceeds with booting the kernel image. I doesnt boot the TFTP recovery.

how should we have known you already had a TFTPd set up ?
the error is the same if there's an image DL error, as when there's no TFTPd set up.

@kanakshilledar

tested the TFTP server and it is working fine.

tested how ?

@kanakshilledar

I even tried the official image and it also giving the same output.

the issue has nothing to do with the image.

is there a fw on the TFTPd host ?

[kanakshilledar]

I have setup the TFTP server in /opt/tftpboot

TFTP server configuration

$ cat /etc/xinetd.d/tftp 
service tftp
{
	protocol	= udp
	port		= 69
	socket_type	= dgram
	wait		= yes
	user		= nobody
	server		= /usr/sbin/in.tftpd
	server_args	= /opt/tftpboot
	disable		= no
}

Directory listing of /opt/tftpboot

$ ls /opt/tftpboot/ -al
total 7944
drwxrwxrwx 2 nobody root     4096 Jan 16 16:07 .
drwxr-xr-x 7 kanak  kanak    4096 Jan 15 18:47 ..
-rwxrwxrwx 1 nobody root  8126464 Oct 12 07:42 tp_recovery.bin

I tested out the TFTP server by connecting via a different linux machine.

[frollic]

I assume you set the IP of the TFTPd host too ?

[kanakshilledar]

Yes I have my IP set as 192.168.0.66 where the TFTP server is running.

[frollic]

then the only way forward is to wireshark / tcpdump the incoming traffic on the TFTPd host.

btw, I take it you've already tried both WAN and LAN ports when attempting the TFTPd recovery.

[kanakshilledar]

This is my setup I have the my laptop and the router connected via a switch. I have connected the ethernet cable in WAN port of the router only.

I am trying to analyze packets through wireshark.

[frollic]

@kanakshilledar

I have connected the ethernet cable in WAN port of the router only.

WAN is usually the port you shouldn't use.

[kanakshilledar]

Okay I connected it to LAN1 and did a packet capture. In wireshark it is saying tp_recovery.bin octet timeout 1

But on my other linux device the transfer is successful. One more interesting finding
when I access the server from my other device wireshark shows the packets as UDP where as in case of router it is shown as TFTP

[kanakshilledar]

Packet of router

[kanakshilledar]

TFTP access from another device

[frollic]

I'd disable the TFTPd host's firewall, just to be sure.

otherwise, i'm kind out of ideas, except perhaps xinetd doesn't trigger on TFTP packets, while it does on UDP.

[kanakshilledar]

@frollic

disable the TFTPd host's firewal

I dont have any firewall setup on my linux device. Shall I try some other TFTP service?

[frollic]

@kanakshilledar

Shall I try some other TFTP service?

that, or don't make it trigger via xinetd.

[kanakshilledar]

I uninstalled xinetd from my system. I am trying atftpd

$ sudo atftpd --daemon --no-fork --logfile - /opt/tftpboot/
Jan 16 18:48:29 pop-os atftpd[10775.139764800218944]: Advanced Trivial FTP server started (0.7.5)
Jan 16 18:48:29 pop-os atftpd[10775.139764800218944]: atftpd: can't bind port :69/udp

List of open ports

$ sudo netstat -lunp | grep 69
udp        0      0 127.0.0.1:323           0.0.0.0:*                           1069/chronyd        
udp6       0      0 :::69                   :::*                                1/init              
udp6       0      0 ::1:323                 :::*                                1069/chronyd    

udp6 is being used by 1/inid