While working on my project on open vswitch I had to connect mininet hosts to internet to enable some functionalities in mininet hosts. After working on it for two days, I came to realise that its just 4 easy steps. If you are struggling with the same here is the solution.
Step 1: Make sure that your guest OS ie mininet OS is connected to the internet.
In virtualbox network setting make sure that you have a NAT interface enabled that allows you to connect to internet. It will have an ip address like this : 10.0.3.15 ie a class A address
Test by pinging www.google.com to make sure you are connected to internet from the guest OS ie Mininet OS.
Step 2: Start the network
Start a mininet netowrk with a switch and a host or any topology you prefer.
sudo mn --switch ovsk --mac --topo single,2
The above command creates a network with single switch and two hosts.
This will create a switch s1 and two hosts h1 and h2.
Step 3: Connect the guest interface(that connects to the internet) to the ovs bridge
The command used to achieve this is an ovs-vsctl command which is used for quering and configuring openvswitchd(this is a process of openvswitch).
Open an xterm window for s1 as this command does not run directly on mininet.For this you need to ssh the guest OS from the host OS. If you don't know how to do this, you can refer to my earlier post titled "Error: Cannot Connect to Display"
Check the openvswitch configuration using the command: ovs-vsctl show
My switch had the following configuration.
root@mininet-vm:~# ovs-vsctl show
d27a9060-3edf-4ee7-a4cf-09e705c93f56
Bridge "s1"
Controller "ptcp:6634"
Controller "tcp:127.0.0.1:6633"
is_connected: true
fail_mode: secure
Port "s1-eth1"
Interface "s1-eth1"
Port "s1-eth2"
Interface "s1-eth2"
Port "s1"
Interface "s1"
type: internal
ovs_version: "2.0.1"
Now, run the following command to connect eth1 to s1: ovs-vsctl add-port s1 eth1
Check the configuration again using ovs-vsctl show. The new interface that is added has been highlighted in red.
root@mininet-vm:~# ovs-vsctl show
d27a9060-3edf-4ee7-a4cf-09e705c93f56
Bridge "s1"
Controller "ptcp:6634"
Controller "tcp:127.0.0.1:6633"
is_connected: true
fail_mode: secure
Port "eth1"
Interface "eth1"
Port "s1-eth1"
Interface "s1-eth1"
Port "s1-eth2"
Interface "s1-eth2"
Port "s1"
Interface "s1"
type: internal
ovs_version: "2.0.1"
Step 4: Run dhclient on hosts.
Open xterm windows for h1 and h2 and run the following commands. The first command removes the ip from h1-eth0,the second command gets the ip address for h1-eth0 from dhcp server. The second command shows the interface description.
root@mininet-vm:~# ifconfig h1-eth0 0
root@mininet-vm:~# dhclient h1-eth0
root@mininet-vm:~# ifconfig
h1-eth0 Link encap:Ethernet HWaddr 00:00:00:00:00:01
inet addr:10.0.3.16 Bcast:10.0.3.255 Mask:255.255.255.0
inet6 addr: fe80::200:ff:fe00:1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:24 errors:0 dropped:0 overruns:0 frame:0
TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:3304 (3.3 KB) TX bytes:1764 (1.7 KB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:1252 errors:0 dropped:0 overruns:0 frame:0
TX packets:1252 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:151432 (151.4 KB) TX bytes:151432 (151.4 KB)
Now check the internet connectivity using ping.
root@mininet-vm:~# ping www.google.com
PING www.google.com (216.58.216.164) 56(84) bytes of data.
64 bytes from sea15s02-in-f4.1e100.net (216.58.216.164): icmp_seq=14 ttl=54 time=61.9 ms
64 bytes from sea15s02-in-f4.1e100.net (216.58.216.164): icmp_seq=15 ttl=54 time=60.7 ms
^C
--- www.google.com ping statistics ---
15 packets transmitted, 2 received, 86% packet loss, time 14065ms
rtt min/avg/max/mdev = 60.707/61.336/61.965/0.629 ms
Summary:
The command that we have used to achieve internet connectivity to hosts are:
ovs-vsctl add-port s1 eth1
ifconfig h1-eth0 0
dhclient h1-eth0
Step 1: Make sure that your guest OS ie mininet OS is connected to the internet.
In virtualbox network setting make sure that you have a NAT interface enabled that allows you to connect to internet. It will have an ip address like this : 10.0.3.15 ie a class A address
Test by pinging www.google.com to make sure you are connected to internet from the guest OS ie Mininet OS.
Step 2: Start the network
Start a mininet netowrk with a switch and a host or any topology you prefer.
sudo mn --switch ovsk --mac --topo single,2
The above command creates a network with single switch and two hosts.
This will create a switch s1 and two hosts h1 and h2.
Step 3: Connect the guest interface(that connects to the internet) to the ovs bridge
The command used to achieve this is an ovs-vsctl command which is used for quering and configuring openvswitchd(this is a process of openvswitch).
Open an xterm window for s1 as this command does not run directly on mininet.For this you need to ssh the guest OS from the host OS. If you don't know how to do this, you can refer to my earlier post titled "Error: Cannot Connect to Display"
Check the openvswitch configuration using the command: ovs-vsctl show
My switch had the following configuration.
root@mininet-vm:~# ovs-vsctl show
d27a9060-3edf-4ee7-a4cf-09e705c93f56
Bridge "s1"
Controller "ptcp:6634"
Controller "tcp:127.0.0.1:6633"
is_connected: true
fail_mode: secure
Port "s1-eth1"
Interface "s1-eth1"
Port "s1-eth2"
Interface "s1-eth2"
Port "s1"
Interface "s1"
type: internal
ovs_version: "2.0.1"
Now, run the following command to connect eth1 to s1: ovs-vsctl add-port s1 eth1
Check the configuration again using ovs-vsctl show. The new interface that is added has been highlighted in red.
root@mininet-vm:~# ovs-vsctl show
d27a9060-3edf-4ee7-a4cf-09e705c93f56
Bridge "s1"
Controller "ptcp:6634"
Controller "tcp:127.0.0.1:6633"
is_connected: true
fail_mode: secure
Port "eth1"
Interface "eth1"
Port "s1-eth1"
Interface "s1-eth1"
Port "s1-eth2"
Interface "s1-eth2"
Port "s1"
Interface "s1"
type: internal
ovs_version: "2.0.1"
Step 4: Run dhclient on hosts.
Open xterm windows for h1 and h2 and run the following commands. The first command removes the ip from h1-eth0,the second command gets the ip address for h1-eth0 from dhcp server. The second command shows the interface description.
root@mininet-vm:~# ifconfig h1-eth0 0
root@mininet-vm:~# dhclient h1-eth0
root@mininet-vm:~# ifconfig
h1-eth0 Link encap:Ethernet HWaddr 00:00:00:00:00:01
inet addr:10.0.3.16 Bcast:10.0.3.255 Mask:255.255.255.0
inet6 addr: fe80::200:ff:fe00:1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:24 errors:0 dropped:0 overruns:0 frame:0
TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:3304 (3.3 KB) TX bytes:1764 (1.7 KB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:1252 errors:0 dropped:0 overruns:0 frame:0
TX packets:1252 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:151432 (151.4 KB) TX bytes:151432 (151.4 KB)
Now check the internet connectivity using ping.
root@mininet-vm:~# ping www.google.com
PING www.google.com (216.58.216.164) 56(84) bytes of data.
64 bytes from sea15s02-in-f4.1e100.net (216.58.216.164): icmp_seq=14 ttl=54 time=61.9 ms
64 bytes from sea15s02-in-f4.1e100.net (216.58.216.164): icmp_seq=15 ttl=54 time=60.7 ms
^C
--- www.google.com ping statistics ---
15 packets transmitted, 2 received, 86% packet loss, time 14065ms
rtt min/avg/max/mdev = 60.707/61.336/61.965/0.629 ms
Summary:
The command that we have used to achieve internet connectivity to hosts are:
ovs-vsctl add-port s1 eth1
ifconfig h1-eth0 0
dhclient h1-eth0
This comment has been removed by the author.
ReplyDeletei can ssh using the command putty.exe -ssh 192.168.56.102 but when after typing sudo mn i type xterm h1 an eror comes as cannot connect to display...plz suggest how to solve this
ReplyDeleteHi
ReplyDeleteIm new to mininet and sdn floodlight controller concepts.
I could successfully connect with a single switch multiple hosts to INTERNET
but when I’m creating multiple switches, multiple hosts connecting to INTERNET
I see only the hosts connecting to 1st switch are able to ping to Internet, where as the hosts connected to other switches are not reachable.
when I try to debug by sniffing the packets on the interface, I see that the all the traffic is passing through the first switch only where as I expected the other switches should push the packets to the controller.
Am I missing something??
I followed above steps to get internet access from mininet host h1.Even after running dhclient on h1-eth0, it is not serving ip.
ReplyDeleteIt got ip in 10.0.3.x subnet but unable to access internet
DeleteIf i press dhclient h1-eth0 it stucks..is there any problem? an how can i solve it?
ReplyDeleteMany websites offer different advice, but I get stuck on the same command every time. "dhclient h1-eth0". It sticks and doesn't move. Do not know what to do.
DeleteThank you for this tutorial. It worked perfectly for me.
ReplyDeleteThe problem that I have though is that while h1 and h2 can ping www.google.com, I don't seem to be able to ping the hosts from my laptop (which is also connected to the internet).
When I do ping 10.0.2.17 (the IP of h2) from my laptop, 0% of the packets get received. When I ping my laptop from h2 though, it works great. Why is this a one way communication?
This works fine but to address the problem faced by Unknown above (March 1, 2017), add a second interface to the host i.e. h1-eth1 and follow the instructions above.
ReplyDeleteUseful post.
Hi,
ReplyDeleteThank you for sharing useful Blog
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Hello:
ReplyDelete"ovs-vsctl add-port s1 eth1"can not execute this command. error:"cannot create a port name eth1 because eth1 already exist on bridge s1"
moreover if i do " ovs-vsctl show" I am getthing "port eth1- could not open network device eth1"