Frequently Asked Questions FAQ
What is the difference between
External connection node and
External interface node?
It would probably be easier to answer this question with the next two questions, so read ahead. Both of them will be using this example topology:
How can I connect my host computer (the one running IMUNES) to an IMUNES topology?
Suppose you have a topology like the one pictured above, with a WEB and a MAIL servers connected in a local network via a switch (switch1) and you want your host computer to join this LAN. From the left-side IMUNES toolbar, click on
Add new network layer node and then
External connection. Place it on the canvas (ext1 node should appear) and connect it with the switch1 node using the link tool. It should receive an IP address from the LAN subnet. You can change this address in the
Configuration dialog box for this node. Execute the experiment. There should now be a new interface and a new route on your host computer, and if an IPv4/IPv6 addresses are configured as non-empty values, you should see those values set:
[root@IMUNES ~/imunes]# ifconfig i42a80-n6 i42a80-n6: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=28<VLAN_MTU,JUMBO_MTU> ether 42:00:aa:5b:84:00 inet 10.0.0.20 netmask 0xffffff00 broadcast 10.0.0.255 inet6 fe80::4000:aaff:fe5b:8400%i42a80-n6 prefixlen 64 scopeid 0x5 inet6 fc00::20 prefixlen 64 nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL> media: Ethernet autoselect (1000baseT <full-duplex>) status: active [root@IMUNES ~/imunes]# netstat -rn4 Routing tables Internet: Destination Gateway Flags Netif Expire 10.0.0.0/24 link#5 U i42a80-n 10.0.0.20 link#5 UHS lo0 ...
If you now ping the MAIL node from your host computer, you will get a reply:
[root@IMUNES ~/imunes]# ping -c 1 10.0.0.11 PING 10.0.0.11 (10.0.0.11): 56 data bytes 64 bytes from 10.0.0.11: icmp_seq=0 ttl=64 time=0.041 ms --- 10.0.0.11 ping statistics --- 1 packets transmitted, 1 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 0.041/0.041/0.041/0.000 ms
To reach every subnet in your topology from your computer, you need to manually add every route or set a default route as the router node FIREWALL (10.0.0.1).
How can I connect a running IMUNES topology to the internet?
Suppose you have a topology like the one pictured above and you need the test-PC node to connect to a remote site somewhere on the internet. From the left-side IMUNES toolbar, click on
Add new link layer node and then
External interface. Place it on the canvas (UNASSIGNED node should appear) and connect it with the test-PC node using the link tool. Double click on the new node and select a Physical interface from the dropdown menu: you want to select an interface connected to the internet.
NOTE: when you run the experiment, this interface will be 'stolen' from your host computer and it will no longer have access to it - make sure this interface is not the main interface for connecting to the internet, otherwise you will lose the connection.
Also, configure the new interface eth1 IP/MAC addresses and its default route to have an IP address and default route from the subnet of whatever you are connecting it to or delete it if you use DHCP on the test-PC node.
NOTE: the eth1 interface of test-PC node needs to have the same MAC address as the interface you are 'stealing'.
220.127.116.11 or any other address from the test-PC node or if you use DHCP, first run:
root@test-PC:/ # dhclient eth1
to get an IP address and you are good to go.