I think I have found a bug in the DHCP mechanism, or at least it is not the operation I expect. I have a main router with IP 192.168.1.1 and active DHCP, and a second router with IP 192.168.2.1 and active DHCP as well. I connect a LAN port from the main router to the WAN port of the secondary router. Now the computers connected to the second router get IPs of type 192.168.2.x, but if I turn off the secondary router, wait a moment, and turn it on again, the computers get IP from the main router, even surf the Internet for a few seconds, before the secondary router is fully operational. The problem is that when it is already operational the computers that were already on, do not get a new IP from the secondary router, they keep the IP that the main router gave, and they are not in a network or surf the internet. I have to disable the network card and enable it again to obtain an IP of the secondary router.