# create veth100@veth200 on linux
ip link add name veth100 type veth peer name veth200
ip link set veth100 up
ip link set veth200 up 

# span to eth1(I renamed Gigabit... to eth1)
vppctl create host-interface name veth200
vppctl set interface span eth1 destination host-veth200 both
vppctl set int state host-veth200 up

# tcpdump for capturing packets.
tcpdump -ni veth100

# clear span
vppctl set interface span eth1 disable
vppctl set int state host-veth200 down

#0 0x00007f84a37ada7c in ?? () from target:/usr/lib64/libc.so.6

#1 0x00007f84a375fef6 in raise ()

from target:/usr/lib64/libc.so.6

#2 0x00007f84a374a2fc in abort ()

from target:/usr/lib64/libc.so.6

#3 0x0000563c4507b133 in os_panic ()

at /root/pkgmaker_sandbox/build/chengyan/ngrayvpp_v9.2310-rc22/src/vpp/vnet/main.c:421

#4 0x00007f84a3a0c7a9 in debugger ()

at /root/pkgmaker_sandbox/build/chengyan/ngrayvpp_v9.2310-rc22/src/vppinfra/error.c:84

#5 0x00007f84a3a0c560 in cliberror (how_to_die=2,

function_name=0x0, line_number=0,

fmt=0x7f84a3bc919c "%s:%d (%s) assertion `%s' fails")

at /root/pkgmaker_sandbox/build/chengyan/ngrayvpp_v9.2310-rc22/src/vppinfra/error.c:143

#6 0x00007f84a3b28d44 in vlib_log (level=VLIB_LOG_LEVEL_NOTICE,

class=1638400, fmt=0x7f846365a905 "fd %u %U")

at /root/pkgmaker_sandbox/build/chengyan/ngrayvpp_v9.2310-rc22/src/vlib/log.c:131

#7 0x00007f8463642e95 in af_packet_fd_error (uf=0x7f8467a384b0)

at /root/pkgmaker_sandbox/build/chengyan/ngrayvpp_v9.2310-rc22/src/plugins/af_packet/af_packet.c:125

#8 0x00007f84a3b8fdc4 in linux_epoll_input_inline (

vm=0x7f84679e9bc0, node=0x7f84679ec200, frame=0x0,

thread_index=1)

at /root/pkgmaker_sandbox/build/chengyan/ngrayvpp_v9.2310-rc22/src/vlib/unix/input.c:334 

/* make sure we are running on the main thread to avoid use in dataplane     code, for dataplane logging consider use of event-logger */
ASSERT (vlib_get_thread_index () == 0);