Symptom
GRE tunnel is established between C9500 and router to realize that
the traffic between router and C9500 is that the traffic entering C9500 passes through GRE tunnel,
and the traffic exiting C9500 is routed through BGP.
When traceroute a ipv6 address the device connected with C9500 from the device connected with router through GRE tunnel ，there is no response sent out from C9500
switch#traceroute 2001:xx:xx:xx::xx
Type escape sequence to abort.
Tracing the route to 2001:xx:xx:xx::xx
1 2001:xx:xx:xx::xx 1 msec 0 msec 1 msec
2 * * * ★
3 2001:xx:xx:xx::xx 1 msec 0 msec 1 msec
