[  407.009407] PPP generic driver version 2.4.2
[  407.010843] NET: Registered PF_PPPOX protocol family
[  407.013528] l2tp_core: L2TP core driver, V2.0
[  407.014468] l2tp_ppp: PPPoL2TP kernel driver, V2.0
[  411.396898] iperf3 (11362) used greatest stack depth: 11496 bytes left
[  411.439520] ppp0: recursion detected
[  411.789894] ppp0: recursion detected
[  412.453100] ppp0: recursion detected