[ 1548.546024][T19951] gre: GRE over IPv4 demultiplexer driver
[ 1549.051225][T19982] ip_gre: GRE over IPv4 tunneling driver
[ 1565.066987][T20649] ip6_gre: GRE over IPv6 tunneling driver
[ 1570.645440][T20938] ping (20938) used greatest stack depth: 23072 bytes left
[ 1575.584690][    C2] ip6_tunnel: tep0 xmit: Local address not yet configured!
[ 1577.632659][    C2] ip6_tunnel: tep0 xmit: Local address not yet configured!
[ 1579.489646][    C1] ip6_tunnel: tep0 xmit: Local address not yet configured!
[ 1581.536650][    C2] ip6_tunnel: tep0 xmit: Local address not yet configured!