如何將特定的環回埠重定向到另一個地址

我想將 postgres 的埠重定向到另一個正在執行 postgres 的地址。postgres 的實例託管在具有僅主機網路配置的 virtualbox 機器上。不幸的是，以下規則似乎無法勝任

echo "rdr pass inet proto tcp from any to 127.0.0.1 port 5432 -> 

172.16.0.2 port 5432" | sudo pfctl -ef -
pfctl: Use of -f option, could result in flushing of rules
present in the main ruleset added by the system at startup.
See /etc/pf.conf for further details.

No ALTQ support in kernel
ALTQ related functions disabled
pfctl: pf already enabled

$ psql -h 127.0.0.1 -p 5432 -U em3local
psql: could not connect to server: Network is unreachable

它出什麼問題了？

當然，如果我嘗試連接到 172.16.0.2 我可以正確訪問它：

$psql -h 172.16.0.2 -p 5432 -U em3local
Password for user em3local: 

這些是我目前的介面（注意最後一個vboxnet0）：

$ ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
   options=3<RXCSUM,TXCSUM>
   inet6 ::1 prefixlen 128 
   inet 127.0.0.1 netmask 0xff000000 
   inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
   inet 172.16.0.9 netmask 0xffff0000 
   nd6 options=1<PERFORMNUD>
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
en0: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
   options=10b<RXCSUM,TXCSUM,VLAN_HWTAGGING,AV>
   ether 38:c9:86:4f:bd:74 
   inet6 fe80::3ac9:86ff:fe4f:bd74%en0 prefixlen 64 scopeid 0x4 
   inet 10.0.0.2 netmask 0xffff0000 broadcast 10.0.255.255
   nd6 options=1<PERFORMNUD>
   media: autoselect (1000baseT <full-duplex,flow-control,energy-efficient-ethernet>)
   status: active
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
   ether 08:6d:41:e9:79:7e 
   inet6 fe80::a6d:41ff:fee9:797e%en1 prefixlen 64 scopeid 0x5 
   inet 10.0.1.2 netmask 0xffff0000 broadcast 10.0.255.255
   nd6 options=1<PERFORMNUD>
   media: autoselect
   status: active
en2: flags=963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX> mtu 1500
   options=60<TSO4,TSO6>
   ether 2a:00:01:66:53:30 
   media: autoselect <full-duplex>
   status: inactive
en3: flags=963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX> mtu 1500
   options=60<TSO4,TSO6>
   ether 2a:00:01:66:53:31 
   media: autoselect <full-duplex>
   status: inactive
p2p0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2304
   ether 0a:6d:41:e9:79:7e 
   media: autoselect
   status: inactive
awdl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1484
   ether 4a:00:05:4b:ef:d9 
   inet6 fe80::4800:5ff:fe4b:efd9%awdl0 prefixlen 64 scopeid 0x9 
   nd6 options=1<PERFORMNUD>
   media: autoselect
   status: active
bridge0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
   options=63<RXCSUM,TXCSUM,TSO4,TSO6>
   ether 3a:c9:86:f4:af:00 
   Configuration:
       id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
       maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
       root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
       ipfilter disabled flags 0x2
   member: en2 flags=3<LEARNING,DISCOVER>
           ifmaxaddr 0 port 6 priority 0 path cost 0
   member: en3 flags=3<LEARNING,DISCOVER>
           ifmaxaddr 0 port 7 priority 0 path cost 0
   nd6 options=1<PERFORMNUD>
   media: <unknown type>
   status: inactive
ppp0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1280
   inet 10.0.0.2 --> 10.0.2.3 netmask 0xffff0000 
vboxnet0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
   ether 0a:00:27:00:00:00 
inet 172.16.0.1 netmask 0xfff00000 broadcast 172.31.255.255

當您將埠從環回設備轉發到其他主機（虛擬主機）時，轉發數據包的源地址不會更改。但它具有相同的環回 IP 地址127.0.0.1。當其他主機（虛擬主機）收到轉發的數據包時，它會回復自己的環回設備。這就是你沒有連接的原因。

在您的主機伺服器上使用其他 ip（不是來自環回的 127.0.0.0/8 網路）進行埠轉發。

引用自：https://serverfault.com/questions/857088