linux: ifconfig and route v.s. new ip command

Configure an interface
ifconfig eth0 10.20.30.153 netmask 255.255.255.240  # old
ip addr add 10.2.30.153/28 dev eth0                 # new
Add a default route
route add default gw 192.168.4.1                    # old
ip route replace default via 192.168.4.1            # new
View the routing table
old route -n                    # old
new ip route show               # new
Add a host route
route add -host 192.168.4.2 eth0                    # old
ip route add 192.168.4.2 dev eth0                   # new
Add a network route
route add -net 192.168.4.0 netmask 255.255.255.0 eth0  # old
ip route add 192.168.4.0/24 dev eth0                   # new
Add a network route through a gateway
route add -net 192.168.5.0 netmask 255.255.255.0 gw 192.168.4.1  # old
ip route add 192.168.5.0/24 via 192.168.4.1                      # new