IIRC somewhere I read that L2TP is only support fastpath in RX and I experience this too. I use simple L2TPv2 tunnel without IPSec, IPv4, IPv6, MPLS inside of it and L2TP only fastpath-ed RX traffic. Is there a way to activating TX fastpath too?
I tested without MPLS and only RX fastpath works even I disable keepalive. Is there anybody whom can using L2TP with fastpath in both direction?
Or is there alternative UDP tunnel technology, which I can use, Branch side behind ISP’s NAT and MPLS L3VPN goes though it?