Problem on CentOS 7.3

[L1H0n9Jun]

lsb_release -a
LSB Version: :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch
Distributor ID: CentOS
Description: CentOS Linux release 7.3.1611 (Core)
Release: 7.3.1611
Codename: Core

./thu6tunnel.sh
delete tunnel "sit1" failed: No such device
RTNETLINK answers: File exists

请问这是咋回事
附
netstat -nr
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 166.111.130.1 0.0.0.0 UG 0 0 0 eno1
166.111.130.0 0.0.0.0 255.255.255.0 U 0 0 0 eno1
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eno1
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0

ifconfig
sit1: flags=209<UP,POINTOPOINT,RUNNING,NOARP> mtu 1480
inet6 2402:f000:1:1501:200:5efe:a66f:822b prefixlen 64 scopeid 0x0
inet6 fe80::a66f:822b prefixlen 128 scopeid 0x20
sit txqueuelen 1 (IPv6-in-IPv4)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

[L1H0n9Jun]

ping6 ipv6.google.com 不通