Part 5: Advanced Networking
Networking Basics
Devices use biosdevname (enp3s0f0)
User ip link
to view interfaces
nmcli is your friend. nmcli tab tab will show you the way.
nmcli connection add con-name enp3s0f2 ipv4.addresses 172.16.0.2/24 ifname enp3s0f2 type ethernet method=manual
Bridges
Create a new bridge.
nmcli connection add type bridge ifname Guests
Add ports
nmcli con add type ethernet con-name br-guest0 ifname enp3s0f0 master Guests
nmcli con add type ethernet con-name br-guest1 ifname enp3s0f1 master Guests
brctl show

Routing
ip route show
- Print current route table
ip route add 10.10.10.0/24 via 192.168.1.12/2
- Add static route to runtime
Edit /etc/sysconfig/network-scripts/route-ifname
- Add persistently route
add a line: 10.0.0.0/24 via 192.168.4.20 dev device
Teaming
Starting a team doesn't bring up a slave port.
Starting a slave port will start the team.
See examples - man nmcli-examples
ls /usr/share/doc/teamd-1.27/example_configs
cp /usr/share/doc/teamd-1.27/example_configs/broadcast.conf team0.json
vim team0.json
{
"device": "team0",
"runner": {"name": "broadcast"},
"ports": {"enp3s0f0": {}, "enp3s0f1": {}}
}
nmcli con add type team con-name Team1 ifname Team1 config team0.json
nmcli con add type team-slave con-name Team0-s1 ifname enp3s0f0 master Team0
nmcli con add type team-slave con-name Team0-s2 ifname enp3s0f1 master Team0
teamctl team0 state
reboot the node.
Add a VLAN.
This example will add vlan 10 to device team0 called corp
nmcli con add type vlan con-name corp ifname team0.10 dev team0 id 10
Bring up an interface
nmcli con up team0
teamdctl team0 state
IPv6 Basics
- 128bit addresses
- Leading zeros can be omitted
fe80::1 - Default subnet /64
- Ports are defined with address in square brackets
[fe80::1]:80
This example is localhost port 80 - MAC address may be part of the node bits.
Predefined Address Spaces
- ::1/128 - localhost
- :: - unspecified address (0.0.0.0)
- ::/0 - default route
- 2000::/3 - global unicast address
- fd00::/8 - unique local address
- fe80::/64 - link-local address
- ff00::/8 - multicast
- No more broadcasts
Obtaining addresses
- nmcli used for static addressing
- fe80:: is used by default
- DHCPv6
muticast sent to ff02::1:2 port 547/UDP (All DHCP Server Multicast)
DHCP server sends packet to client port 548/UDP - SLAAC - Stateless Address Auto Configuration
Router solicitation sent to ff02::2 (All routers multicast)
Router provides address to host with network prefix (radvd needed)
Setting a manual address
nmcli con modify eth0 ipv6.method manual ipv6.addr fd00:201/64
nmcli con modify eth0 +ipv6.dns fd00:200/64
Setting the method is extremely important.