Hi, I posted last year about a problem I was having with Linux's PPPoE functionality in regards to a specific modem. At the time I put it down to a dodgy modem and moved on, but now I've hit it on another modem, and twice seems more than coincidence. The problem is that path MTU detection seem to break when the "bad" modems are involved. So the Linux box running pppoe is OK, because it knows the interface has an mtu+mru of 1492, but masqueraded clients do not. You can work around the problem a bit, by having an iptables rule with --clamp-mss-to-pmtu, but it's a kludge.. and importantly, only required for two of these four modems. The other two work just fine *with apparently identical configurations* (ie. LLC / bridged) Can anyone think of a reason for this? The rp-pppoe and other mailing lists offer tantalising hints that I'm not alone, but sadly those threads do not lead to any solutions. Modems that work: * TP-Link TD-8817 (Trendchip chipset) * Billion 7300RA (Trendchip chipset) Modems that don't work: * TP-Link TD-8840T (Trendchip) * Billion 7800NL (Broadcom chipset)