IP forwarding on public IPs

Comments

• tentor Member, Host Rep

  September 2023 edited September 2023

  Use DNAT

  Thanked by 2yoursunny sebkehl
• LittleCreek Member, Patron Provider

  September 2023

  @tentor said:
  Use DNAT

  So you use DNAT on public IPs as well? I thought that would only be for private addresses.
• tentor Member, Host Rep

  September 2023

  Sure

  vm $ mtr -c 1 -w 8.8.8.8 # before DNAT
  Start: 2023-09-14T13:52:34+0200
  HOST: backend-replica  Loss%   Snt   Last   Avg  Best  Wrst StDev
    1.|-- _gateway          0.0%     1    0.1   0.1   0.1   0.1   0.0
    2.|-- 192.168.0.2       0.0%     1    0.1   0.1   0.1   0.1   0.0
    3.|-- pl.skhron.com.ua  0.0%     1   29.5  29.5  29.5  29.5   0.0
    4.|-- 172.30.2.2        0.0%     1    0.4   0.4   0.4   0.4   0.0
    5.|-- ???              100.0     1    0.0   0.0   0.0   0.0   0.0
    6.|-- 108.170.250.193   0.0%     1    1.0   1.0   1.0   1.0   0.0
    7.|-- 108.170.234.245   0.0%     1    1.5   1.5   1.5   1.5   0.0
    8.|-- dns.google        0.0%     1    0.8   0.8   0.8   0.8   0.0
  router $ sudo nft -t -a -i # setup DNAT
  nft> add table inet natexample
  nft> add chain inet natexample prerouting { type nat hook prerouting priority -100; }
  nft> add rule inet natexample prerouting meta l4proto icmp ip daddr 8.8.8.8 dnat to 1.1.1.1
  nft> list table inet natexample
  table inet natexample { # handle 109
      chain prerouting { # handle 1
          type nat hook prerouting priority dstnat; policy accept;
          meta l4proto icmp ip daddr 8.8.8.8 dnat ip to 1.1.1.1 # handle 4
      }
  }
  vm $ mtr -c 1 -w 8.8.8.8 # after DNAT
  Start: 2023-09-14T13:52:18+0200
  HOST: backend-replica Loss%   Snt   Last   Avg  Best  Wrst StDev
    1.|-- _gateway         0.0%     1    0.1   0.1   0.1   0.1   0.0
    2.|-- dns.google       0.0%     1    0.1   0.1   0.1   0.1   0.0
  
  

  Thanked by 4QDE Patriarch sebkehl Egyarmy