Changes between Version 1 and Version 2 of JoeSandbox/OpenFlowNATTremaExample/Execute


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Timestamp:
08/27/14 13:45:43 (5 years ago)
Author:
zwang@bbn.com
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  • JoeSandbox/OpenFlowNATTremaExample/Execute

    v1 v2  
    2020= STEPS FOR EXECUTING EXAMPLE =
    2121
    22 In this section, we are going to build a router for a private address space that needs one-to-many NAT (IP Masquerade) for some reason (e.g. short on public IP or security) using OpenFlow. As shown in the figure below, hosts `inside1` and `inside2` are inside the LAN, while host `outside` is outside. The LAN has only one public IP — '''128.128.129.1'''. (The external IPs we use, 128.128.128.0/24 and 128.128.129.0/24, are just an example. If your public IP happens to be in this subnet, change them to others.)
     22In this section, we are going to build a router for a netwrok with a private address space that needs a one-to-many NAT (IP Masquerade) for some reason (e.g. short on public IP space or security) using OpenFlow. As shown in the figure below, hosts `inside1` and `inside2` are part of the private network, while host `outside` is outside. The LAN has only one public IP — '''128.128.129.1'''. (The external IPs we use, 128.128.128.0/24 and 128.128.129.0/24, are just an example. If your public IP happens to be in this subnet, change them to others.)
    2323
    2424[[Image(openflow-nat.png, 50%, nolink)]] 
     
    2626=== 1.1 Login to your hosts ===
    2727
    28 To start our experiment we need to ssh all of our hosts. Depending on which tool and OS you are using there is a slightly different process for logging in. If you don't know how to SSH to your reserved hosts take a look in [wiki:HowTo/LoginToNodes this page.] Once you have logged in, follow the rest of the instructions.
     28To start our experiment we need to ssh into all of our hosts. Depending on which tool and OS you are using there is a slightly different process for logging in. If you don't know how to SSH to your reserved hosts take a look in [wiki:HowTo/LoginToNodes this page.] Once you have logged in, follow the rest of the instructions.
    2929
    3030=== 1.2 Test reachability ===
    3131
    32 a. First we start a ping from `inside1` to `inside2`, which should also work since they are inside the same LAN.
     32a. First we start a ping from `inside1` to `inside2`, which should work since they are both inside the same LAN.
    3333{{{
    3434inside1:~$ ping 192.168.0.3 -c 10
     
    4242c. Similarly, we cannot ping from `insideX` to `outside`.
    4343
    44 d. You can also use Netcat(nc) to test reachability of TCP and UDP. The behavior should be the same.
     44d. You can also use Netcat (`nc`) to test reachability of TCP and UDP. The behavior should be the same.
    4545
    4646== 2 Start controller to enable NAT ==
    4747
    48 === 2.1 Inside source ===
    49 '''We definitely need a better naming for this one'''
     48=== 2.1 Access a server from behind the NAT ===
    5049
    51 You can try to write your own controller to implement NAT. However, we've provided you a functional controller, which is a file called nat.rb under /tmp/ .
     50You can try to write your own controller to implement NAT. However, we've provided you a functional controller, which is a file called `nat.rb` under `/tmp/` .
    5251
    53 a. Start the controller on `switch` host:
     52a. Start the controller on `NAT` host:
    5453{{{
    55 switch:~$ trema run /tmp/nat.rb
     54nat:~$ trema run /tmp/nat.rb
    5655}}}
    5756You should see following log after the switch is connected to the controller
     
    7877Note that there should be only one log per connection, because the rest of the communication will re-use the mapping.
    7978
     79{{{
     80#!comment
    8081=== 2.2 Outside source ===
    8182
     
    105106
    106107e. Common solution of handling outside source is providing some way to manually create mapping in advance. We will leave it as an exercise for you to implement it.
     108}}}
    107109
    108110== 3 Handle ARP and ICMP ==
     
    134136You should see it's receiving two groups of icmp packets, differentiated by icmp_id.
    135137
     138{{{
     139#!comment
    136140d.
    137141Note that, again, you cannot start the ping from the outside, similar to TCP/UDP. The common solution is to manually map the ping destination to a specific inside IP in advance. We will leave it as an exercise for you to implement it, as well.
    138 
     142}}}
    139143
    140144