Shell – How to monitor all outgoing requests/connections from the machine

You can use lsof and watch to do this, like so:

$ watch -n1 lsof -i TCP:80,443

Example output

dropbox    3280 saml   23u  IPv4 56015285      0t0  TCP greeneggs.qmetricstech.local:56003->snt-re3-6c.sjc.dropbox.com:http (ESTABLISHED)
thunderbi  3306 saml   60u  IPv4 56093767      0t0  TCP greeneggs.qmetricstech.local:34788->ord08s09-in-f20.1e100.net:https (ESTABLISHED)
mono       3322 saml   15u  IPv4 56012349      0t0  TCP greeneggs.qmetricstech.local:54018->204-62-14-135.static.6sync.net:https (ESTABLISHED)
chrome    11068 saml  175u  IPv4 56021419      0t0  TCP greeneggs.qmetricstech.local:42182->stackoverflow.com:http (ESTABLISHED)

Two things could be the cause of this:

One possible cause is the way you've built the private network (using the bridge on the host). It would be much safer and easier to configure this using virt-manager. If your host is CLI only, install it on a remote desktop/laptop and connect over SSH to the host.

Once installed, connect to the hypervisor, right click on it's name in the list and choose 'Details'. On the 'Virtual Networks' tab you can add a new network by clicking on the '+' button (lower,left). The wizard will guide you through the process, but make sure you un-check the options for IPv4 and IPv6 addresses (you don't need them as it's a point-to-point link) and choose the radio button for 'Private network'. Continue with the wizard and exit.

If you're a die-hard command line only person, then the above can be carried out using the virsh net-define command line interface. Create an XML file such as the example below (virbr2 is an unused bridge name - use brctl show to list yours):

<network>
    <name>private</name>
    <bridge name="virbr2" />
</network>

Then import it with:

# virsh net-define <XML filename>

Once the above is done, you can edit each VM to use this new private network (you'll have to reboot the VMs for this to take effect). Once you've edited the VM configuration, you'll be ready to log in to each one and configure the OS with the relevant IP details (from your OP). But, read on first...

Secondly, you have no routes between the two VMs pointing to the new interfaces. Another This is because you've configured the IP address with a /32 prefix.

When editing the connection use the format a.b.c.d/p to set the prefix; otherwise, without a prefix, it will default to /32:

# nmcli con edit "Wired connection 1"
nmcli> set ipv4.addresses 10.1.1.1/30
nmcli> save
nmcli> quit
# systemctl restart network

Configuring the network manually also works:

NM_CONTROLLED=no
TYPE=Ethernet
BOOTPROTO=none
ONBOOT=yes
IPADDR=10.1.1.1
PREFIX=30

Carry out a similar procedure on the other VM (10.1.1.2/30) and it should work.

Note: You could use /31 but only if you changed the IP addresses to 10.1.1.0 and 10.1.1.1. This may cause problems as the first address in the range is usually reserved for the network address and the last for broadcast. As you only have two addresses with /31, you'd have none left for the hosts. Best stick with /30, which gives you 4 addresses - two reserved and two for your hosts.