Why does the router not connect via pppoe from one provider, but not from another?

Question

Iron

So here's the story. I sat on Dom.ru, and I had a PLATINUM 3G WIFI router, connected via pppoe, worked. We decided to switch to TTK (favorable conditions). But the router refused to connect, gave an error when negotiating with the peer. They took another router - DIR 615.
A year later, the same problem began with a new router. I checked it directly (connected from a computer) - it works. For the sake of experiment, I connected an old router, it worked (surprisingly!?), But the quality of its wifi signal left much to be desired. They invited a technician, he checked the connection through the PC, poked around in the router, updated the firmware, nothing helped, he advised me to take a new router.
When we returned to Dom.ru, DIR 615 connected smoothly and works without errors.
How can this be? It can be assumed that the TTK has a problem, but still I wonder why the PC was connected, but the working router was not?

Answer 1

There may be several reasons. The most surprising that was in my practice: the colors of the twisted pair in the switching box in the entrance were mixed up. At the same time, everything worked "directly", the network card was able to figure it out. But through the ASUS router - no way. Just in case, check the correctness of the crimp from your end. If you have 4 wires, then the standard should be like this: if there are 8 wires, then like this:

Answer 2

Dom.ru has the so-called russian ppoe, that is, ppoe without getting an address on the local area before connecting. TTC is different. Some routers don't have enough settings to see the difference. Plus, some routers just behave differently. With D-Link for Dom.Ru, you need to choose Dhcp + pppoe, which works more stable, although, in fact, this is NoIp + pppoe. And on other routers, just noip + pppoe works.
That is, there may be a jamb in the firmware, or the necessary setting is missing.