Examples:

• add a plain route to network 10.0.0/24 via gateway 193.233.7.65

    ip route add 10.0.0/24 via 193.233.7.65
  

• change it to a direct route via the dummy device

    ip ro chg 10.0.0/24 dev dummy
  

• add a default multipath route splitting the load between ppp0 and ppp1

    ip route add default scope global nexthop dev ppp0 \
                                      nexthop dev ppp1
  

  Note the scope value. It is not necessary but it informs the kernel that this route is gatewayed rather than direct. Actually, if you know the addresses of remote endpoints it would be better to use the via parameter.
• announce that the address 192.203.80.144 is not a real one, but should be translated to 193.233.7.83 before forwarding

    ip route add nat 192.203.80.144 via 193.233.7.83
  

  Backward translation is setup with policy rules described in the following section (sec.8, p.).