GCP Instance Multiple Network Interface Access Problem

 GCP 上面創建Instance時，如果有多個network interface設定，需要額外創建routing rule

 

1. 
   nic 0 / default / 10.140.0.2
   nic 1 / interface-1 / 10.40.0.2
   nic 2 / interface-2 / 10.60.0.2
   
   
2. 
   創建好VM後，進入linux
   
   
3. 
   sudo echo "100 rt1" | sudo tee -a /etc/iproute2/rt_tables
   sudo echo "200 rt2" | sudo tee -a /etc/iproute2/rt_tables 
   
4. 
   vim /root/iproute.sh
   
   #!/bin/bash
   
   sleep 10
   ip route add 10.40.0.1 src 10.40.0.2 dev eth1 table rt1
   ip route add default via 10.40.0.1 dev eth1 table rt1
   ip rule add from 10.40.0.2/32 table rt1
   ip rule add to 10.40.0.2/32 table rt1
   
   ip route add 10.60.0.1 src 10.60.0.2 dev eth2 table rt2
   ip route add default via 10.60.0.1 dev eth2 table rt2
   ip rule add from 10.60.0.2/32 table rt2
   ip rule add to 10.60.0.2/32 table rt2
   
   
5. 注意一定要 sleep 10 (因為google 執行 startup-scritp的時候，有可能network interface還沒啟動)
   
   
6. 
   在 Instance 加入 metadata :
   metadata key : startup-script
   metadata value :
   
   #!/bin/bash
   /root/iproute.sh
   
   
   
7. 重新啟動 instance，應該就可以正常存取
8. 可以去 /var/log/message 看啟動資訊，關鍵字 GCEMetadataScripts