pfSense

https://forum.pfsense.org/index.php?topic=41061.0

long thread but to me it seems the nic drivers is the culprit, the only was i can get it to connect is to force the nic to disable and then enable as rebooting resets the nic thats y it then connects, regarding modems, i have tried it many different modems, isps and in difeerent countries, the issue still remains with the alix nic having the via chipset

The actual hardware is a BT Voyager 190 Ethernet ADSL modem with the unlocked firmware on it.

I assume that the issue is resolvable on the pfsense side as a reboot of the pfsense box reconnects without anything being done to the Ethernet model (as stated the ADSL stays up all the time).

not the modem, what hardware are you running pfSense on, specifically what NICs but other details might help.

for me alix via chipset and 2 full install machines with realtek chipset have this issue

It's a virtual machine on ESX, using E1000 nics, the NIC isn't locked however as the web interface on the ADSL modem can be accessed and the only route to that is via the pfSense box.

Ok that's a different circumstance from the other I mentioned (which is the same as what Bipin noted). That's never applied to Intel NICs, and wouldn't apply to ESX as those NICs never lose link in that circumstance.

What do your PPPoE logs show at the time? If you packet capture on WAN (no filtering, count 0, let it run for 15-30 seconds or so and stop), what does that look like? Can email me the resulting pcap file (cmb at pfsense dot org) with reference to this ticket.