Hello everyone,
I have been using OpenWRT router for a month, which is connected to my old router. The problem had appeared, when I connected it directly to my ISP. Basic research showed that the router cannot get ip from ISP https://pastebin.com/0xu1JuHs (My ISP has no mac addresses whitelist. I can use any device with any mac). The reason is either ISP ignores DHCP broadcast or signal fades out in the middle. I wrote to tech support, and they replied, that problem is in my device and requests payment to solve it.
First, I had returned to stock firmware and there was no connection problem. So that is not a hardware defect. Then I had connected my laptop via udhcpc utility and there also weren't any troubles https://pastebin.com/VRaRRmBb. Finally, I had connected a router to my laptop to confirm there is no misconfigured firewall and tried to send a message from last device. Everything worked fine https://pastebin.com/XwiPEQDc.
So I can only assume that signal fades out in the middle because of OpenWRT firmware. Unfortunately, I don't know which length of twisted pair/optical fiber is needed to reproduce it.
The only solution I have is connection through another router.
By the way, I have tried to set static ip address and changed lan port to wan, but it didn't help.
Perhaps configure a valid, but different, MAC address on your WAN interface, just to test for the rare case of your router not having a unique MAC and your ISP stumbling over two CPEs with the same MAC.
This appears to be a rather ordinary MT7621 box so OpenWrt is well proven on that chip. What does the log say when you disconnect and reconnect the Ethernet cable to the WAN port?
I wouldn't modify anything about the MAC address, to be honest. I see no reason why this is breaking anything, especially when it comes at the cost of writing stuff with an i_want_a_brick option.
@tty: Try hooking up your laptop's ethernet port to the wan port of the router and run tcpdump on the laptop's port and verify that the router sends a proper readable DHCP request on that port.
Also the ISPs reply looks rather fishing.
13:39:33.571881 IP 10.10.10.10.67 > 255.255.255.255.68: BOOTP/DHCP, unknown (0x71), length 11
That's unlikely to be a valid DHCP response, despite the originator port clearly being a dhcp server. Some sort of corruption?
i_want_a_brick option is just to indicate that we should not do anything especially if we are on the bootloader
*
there as we do not touch mtd0 but the factory mtd2.bin
Yes length is only 11 suggests it is a rejection. Use tcpdump -vv to decode the packet.
If your MAC on the wire starts with 16: that is a valid MAC, but it has the locally administered bit set meaning it should not be in the factory table.