问题
I decided to add a tap interface and use it in my code , but I am able to get its state UP.
sudo ip -f link tuntap add tap10 mode tap
sudo ip link set tap10 up
After this when I do "ip link"
tap10: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 500
link/ether 26:cc:d2:b4:37:ea brd ff:ff:ff:ff:ff:ff
state DOWN: How to get this state UP ? I am trying to send packets to it and nothing is received .
回答1:
It turns out that you need to have a proccess that uses your tap interface in order for it to be active.
This means that you need to write or use a program that connects to the interface file descriptor, then it will change its state to "RUNNING".
来源：https://stackoverflow.com/questions/22570906/tap-interface-not-coming-up