[ 3959.417592][T19966] gre: GRE over IPv4 demultiplexor driver
[ 3961.461817][T19989] ip_gre: GRE over IPv4 tunneling driver
[ 4023.361060][T20562] ip6_gre: GRE over IPv6 tunneling driver
[ 4059.298912][T20906] ping (20906) used greatest stack depth: 21920 bytes left
[ 4065.279888][    C2] ip6_tunnel: tep0 xmit: Local address not yet configured!
[ 4071.231842][    C3] ip6_tunnel: tep0 xmit: Local address not yet configured!
[ 4076.159859][    C1] ip6_tunnel: tep0 xmit: Local address not yet configured!
[ 4081.983821][    C2] ip6_tunnel: tep0 xmit: Local address not yet configured!