All of this configuration will happen automatically if you choose
Yes, configure /etc/network/interfaces in the Setup wizard. If for some reason you need to configure
/etc/network/interfaces manually, you can do the following.
NOTE! You may lose network connectivity during this process! Have a backup plan if attempting over SSH!
Stop Network Manager:
sudo /etc/init.d/network-manager stop
Prevent Network Manager from starting at next boot:
sudo mv /etc/init/network-manager.conf /etc/init/network-manager.conf.DISABLED
Next, configure your network interfaces in
You’ll want a management interface (preferably connected to a dedicated management network) using either DHCP OR preferably static IP.
You’ll want one or more interfaces dedicated to sniffing (no IP address). NIC offloading functions such as
gro should be disabled to ensure that Snort/Suricata/Zeek get an accurate view of the traffic (see https://blog.securityonion.net/2011/10/when-is-full-packet-capture-not-full.html).
auto lo iface lo inet loopback # Management interface using DHCP auto eth0 iface eth0 inet dhcp # OR # Management interface using STATIC IP (instead of DHCP) auto eth0 iface eth0 inet static address 192.168.1.14 gateway 192.168.1.1 netmask 255.255.255.0 network 192.168.1.0 broadcast 192.168.1.255 dns-nameservers 192.168.1.1 192.168.1.2 # AND one or more of the following # Connected to TAP or SPAN port for traffic monitoring auto eth1 iface eth1 inet manual up ifconfig $IFACE -arp up up ip link set $IFACE promisc on down ip link set $IFACE promisc off down ifconfig $IFACE down post-up for i in rx tx sg tso ufo gso gro lro; do ethtool -K $IFACE $i off; done post-up echo 1 > /proc/sys/net/ipv6/conf/$IFACE/disable_ipv6 # You probably don't need to enable or edit the following setting, # but it is included for completeness. # Note that 4096 is just an example and your NIC may have a different maximum rx size. # To determine the maximum rx setting for your NIC: ethtool -g ethX # Also note that increasing beyond the default may result in inconsistent traffic: # https://taosecurity.blogspot.com/2019/04/troubleshooting-nsm-virtualization.html # post-up ethtool -G $IFACE rx 4096
sudo /etc/init.d/networking restart
If you already had sensors running on these interfaces, you should restart them:
For more information on network configuration in Ubuntu, please see https://help.ubuntu.com/community/NetworkConfigurationCommandLine/Automatic.
Security Onion is designed to use wired interfaces. We don’t recommend or support wireless interfaces. If you absolutely must use a wireless interface for your management interface, you may be able to make it work by removing it from
/etc/network/interfaces and restarting the network manager service. For more information, please see https://groups.google.com/d/topic/security-onion/aC4psdszC58/discussion.