---
# System prepended metadata

title: Mininet 6 router_-on-a-stick

---

# Mininet 6 router_-on-a-stick


Router on a stick 

透過 單個 Trunk link 實現 2 個以上 Interface Connection 

會用到 Vlan 的Concept 

![](https://i.imgur.com/LdTZqG6.png)


```
apt install vlan
```


## Configure Virtual Interface 


實體介面 + Lable ID 

這裡的10跟20 -> 是指 lable 標籤 判斷要送給哪個virtual interface 

```
  br1.cmd("vconfig add br1-eth4 10")
  br1.cmd("vconfig add br1-eth4 20")
  
  r1.cmd("vconfig add r1-eth0 10")
  r1.cmd("vconfig add r1-eth0 20")
```

## Python Script 

```
#! /usr/bin/env python
from mininet.cli import CLI
from mininet.net import Mininet
from mininet.link import Link,TCLink,Intf

if '__main__' == __name__:
  net = Mininet(link=TCLink)
  h1 = net.addHost('h1')
  h2 = net.addHost('h2')
  h3 = net.addHost('h3')
  h4 = net.addHost('h4')
  br1 = net.addHost('br1')
  r1 = net.addHost('r1')
  net.addLink(h1, br1)
  net.addLink(h2, br1)
  net.addLink(h3, br1)
  net.addLink(h4, br1)
  net.addLink(br1,r1)
  net.build()
  h1.cmd("ifconfig h1-eth0 0")
  h2.cmd("ifconfig h2-eth0 0")
  h3.cmd("ifconfig h3-eth0 0")
  h4.cmd("ifconfig h4-eth0 0")
  r1.cmd("ifconfig r1-eth0 0")
  br1.cmd("ifconfig br1-eth0 0")
  br1.cmd("ifconfig br1-eth1 0")
  br1.cmd("ifconfig br1-eth2 0")
  br1.cmd("ifconfig br1-eth3 0")
  br1.cmd("ifconfig br1-eth4 0")
  br1.cmd("vconfig add br1-eth4 10")
  br1.cmd("vconfig add br1-eth4 20")
  r1.cmd("vconfig add r1-eth0 10")
  r1.cmd("vconfig add r1-eth0 20")
  br1.cmd("brctl addbr mybr10")
  br1.cmd("brctl addbr mybr20")
  br1.cmd("brctl addif mybr10 br1-eth0")
  br1.cmd("brctl addif mybr10 br1-eth1")
  br1.cmd("brctl addif mybr10 br1-eth4.10")
  br1.cmd("brctl addif mybr20 br1-eth2")
  br1.cmd("brctl addif mybr20 br1-eth3")
  br1.cmd("brctl addif mybr20 br1-eth4.20")
  br1.cmd("ifconfig br1-eth4.10 up")
  br1.cmd("ifconfig br1-eth4.20 up")
  r1.cmd("ifconfig r1-eth0.10 up")
  r1.cmd("ifconfig r1-eth0.20 up")
  br1.cmd("ifconfig mybr10 up")
  br1.cmd("ifconfig mybr20 up")
  r1.cmd('ifconfig r1-eth0.10 192.168.10.254 netmask 255.255.255.0')
  r1.cmd('ifconfig r1-eth0.20 192.168.20.254 netmask 255.255.255.0')
  r1.cmd("echo 1 > /proc/sys/net/ipv4/ip_forward")
  h1.cmd("ip address add 192.168.10.1/24 dev h1-eth0")
  h1.cmd("ip route add default via 192.168.10.254")
  h2.cmd("ip address add 192.168.10.2/24 dev h2-eth0")
  h2.cmd("ip route add default via 192.168.10.254")
  h3.cmd("ip address add 192.168.20.1/24 dev h3-eth0")
  h3.cmd("ip route add default via 192.168.20.254")
  h4.cmd("ip address add 192.168.20.2/24 dev h4-eth0")
  h4.cmd("ip route add default via 192.168.20.254")
  CLI(net)
  net.stop() 

```

R1 Interface setting 

![](https://i.imgur.com/mAAZdDo.png)


---

br1 Interface setting 

![](https://i.imgur.com/O9xyVBV.png)

---

![](https://i.imgur.com/reOuSz9.png)


```
  br1.cmd("brctl addif mybr10 br1-eth0")
  br1.cmd("brctl addif mybr10 br1-eth1")
  br1.cmd("brctl addif mybr10 br1-eth4.10")
  br1.cmd("brctl addif mybr20 br1-eth2")
  br1.cmd("brctl addif mybr20 br1-eth3")
  br1.cmd("brctl addif mybr20 br1-eth4.20")
```


802.1Q VLAN 


ICMP Request 

![](https://i.imgur.com/SBWPONp.png)


![](https://i.imgur.com/T1zpSo2.png)

---

ICMP Reply 

![](https://i.imgur.com/SSpzhvP.png)


![](https://i.imgur.com/3b4JjXI.png)
