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pingが機能しているときに「ping -vrf」が機能しないのはなぜですか？

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pingが機能しているときに「ping -vrf」が機能しないのはなぜですか？ 
0:root@SERVER:/root # ping IPADDRESS
PING IPADDRESS (IPADDRESS): 56 data bytes
64 bytes from IPADDRESS: icmp_seq=0 ttl=254 time=0 ms
64 bytes from IPADDRESS: icmp_seq=1 ttl=254 time=0 ms
64 bytes from IPADDRESS: icmp_seq=2 ttl=254 time=0 ms
^C
--- IPADDRESS ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 0/0/0 ms
0:root@SERVER:/root # ping -vrf IPADDRESS
PING IPADDRESS (IPADDRESS): 56 data bytes
ping: sendto: Network is unreachable
ping: wrote IPADDRESS 64 chars, ret=-1
.ping: sendto: Network is unreachable
ping: wrote IPADDRESS 64 chars, ret=-1
.ping: sendto: Network is unreachable
ping: wrote IPADDRESS 64 chars, ret=-1
.ping: sendto: Network is unreachable
ping: wrote IPADDRESS 64 chars, ret=-1
.ping: sendto: Network is unreachable
ping: wrote IPADDRESS 64 chars, ret=-1
.ping: sendto: Network is unreachable
ping: wrote IPADDRESS 64 chars, ret=-1
.ping: sendto: Network is unreachable

質問：IPADDRESSをpingできますが、IPADDRESSを「ping -vrf」できないのはなぜですか？

答え1

-rオプションのためです。男性の場合：

   -r     Bypass the normal routing tables and send directly to a host 
          on an attached interface.  If the host is not on a directly-
          attached network, an error is returned.  This option can be 
          used to ping a local host through an interface that has no 
          route through it provided the option -I is also used.

ホストをネットワークに直接接続する必要があります。それ以外の場合は質問のように失敗します。

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