Não é possível alterar as informações de roteamento para o endereço de broadcast no macOS

Question

Estou executando o macOS High Sierra (10.13.4) e tentando fazer com que o tráfego destinado à sub-rede 255.255.255.255/32 passe pela minha interface VPN (utun1).

O comando que tentei usar é:

route change 255.255.255.255/32  -interface utun1

No entanto, isso me dá um erro de route: bad address: 255.255.255.255/32 . Não consigo entender por que isso acontece.

A documentação de route diz isto:

route [-n] command [-net | -host] [-ifscope boundif] destination gateway [netmask]

...

where destination is the destination host or network, gateway is the next-hop intermediary via which packets should be routed. Routes to a particular host may be distinguished from those to a network by interpreting the Internet address specified as the destination argument. The optional modifiers -net and -host force the destination to be interpreted as a network or a host, respectively. Otherwise, if the destination has a ''local address part'' of INADDR_ANY (0.0.0.0), or if the destination is the symbolic name of a network, then the route is assumed to be to a network; otherwise, it is presumed to be a route to a host. Optionally, the destination could also be specified in the net/bits format.

For example, 128.32 is interpreted as -host 128.0.0.32; 128.32.130 is interpreted as -host 128.32.0.130; -net 128.32 is interpreted as 128.32.0.0; -net 128.32.130 is interpreted as 128.32.130.0; and 192.168.64/20 is interpreted as -net 192.168.64 -netmask 255.255.240.0.

Saída de netstat -nr :

Routing tables

Internet:
Destination        Gateway            Flags        Refs      Use   Netif Expire
0/1                10.8.0.1           UGSc           73        0   utun1
default            10.160.16.1        UGSc            1        0     en0
10.8/24            10.8.0.2           UGSc           17        0   utun1
10.8.0.2           10.8.0.2           UH              1        0   utun1
10.160.16/23       link#5             UCS             0        0     en0
10.160.16.1/32     link#5             UCS             1        0     en0
10.160.16.1        b0:aa:77:a2:8e:bf  UHLWIir         5       86     en0    298
10.160.16.10/32    link#5             UCS             0        0     en0
127                127.0.0.1          UCS             0        0     lo0
127.0.0.1          127.0.0.1          UH              7  6945381     lo0
127.0.0.1/32       10.160.16.1        UGSc            0        0     en0
128.0/1            10.8.0.1           UGSc            5        0   utun1
159.89.172.205/32  10.160.16.1        UGSc            1        0     en0
169.254            link#5             UCS             0        0     en0
224.0.0/4          link#5             UmCS            1        0     en0
224.0.0.251        1:0:5e:0:0:fb      UHmLWI          0        0     en0
255.255.255.255    utun1              UHSb            0        0   utun1
255.255.255.255/32 link#5             UCS             0        0     en0

Observe a rota para 255.255.255.255 que eu criei com sucesso usando sudo route add 255.255.255.255 -interface utun1 .

Link para encaminhar a documentação: link