1. ipinip means what?

2. route

172.22.100.192/26 via 192.168.108.1 dev eth1
192.168.19.0/24 via 192.168.108.1 dev eth1
192.168.107.0/24 via 192.168.108.1 dev eth1

blackhole 172.22.100.64/26  proto bird 

192.168.108.0/24 dev eth1 proto kernel scope link src 192.168.108.104 metric 100

Which module add the upline route? felix, bird? How?

3. route reflect is what?

4. BGP工作流程