我有一個 Ubuntu 伺服器，我無法從外部機器訪問伺服器。我試圖通過 ssh 連接到 Ubuntu 機器，但它似乎所有請求都被丟棄或沒有到達。我沒有設置任何特殊的路由或 ip 配置。

子網如下所示：

       router
          |
 ---------+--------------------
 |        |         |         |
Ubuntu  raspberry  raspberry raspberry

首先我通過vpn進入網路，然後我想登錄我的Ubuntu機器但我不能這樣做，所以我嘗試訪問覆盆子，當我看到我可以進入我嘗試的覆盆子時從覆盆子 ssh 到我的 Ubuntu 伺服器，它工作。

從路由器我看到所有的機器。

任何人都可以在不訪問其中一個樹莓的情況下幫助我訪問我的 Ubuntu 伺服器嗎？

sudo iptables-保存

# Generated by iptables-save v1.8.4 on Fri Sep 11 07:58:24 2020
*nat
:PREROUTING ACCEPT [60337:4082282]
:INPUT ACCEPT [5:300]
:OUTPUT ACCEPT [4920:342818]
:POSTROUTING ACCEPT [4920:342818]
:OUTPUT_direct - [0:0]
:POSTROUTING_ZONES - [0:0]
:POSTROUTING_direct - [0:0]
:POST_public - [0:0]
:POST_public_allow - [0:0]
:POST_public_deny - [0:0]
:POST_public_log - [0:0]
:POST_public_post - [0:0]
:POST_public_pre - [0:0]
:PREROUTING_ZONES - [0:0]
:PREROUTING_direct - [0:0]
:PRE_public - [0:0]
:PRE_public_allow - [0:0]
:PRE_public_deny - [0:0]
:PRE_public_log - [0:0]
:PRE_public_post - [0:0]
:PRE_public_pre - [0:0]
-A PREROUTING -j PREROUTING_direct
-A PREROUTING -j PREROUTING_ZONES
-A OUTPUT -j OUTPUT_direct
-A POSTROUTING -j POSTROUTING_direct
-A POSTROUTING -j POSTROUTING_ZONES
-A POSTROUTING_ZONES -o eno1 -g POST_public
-A POSTROUTING_ZONES -g POST_public
-A POST_public -j POST_public_pre
-A POST_public -j POST_public_log
-A POST_public -j POST_public_deny
-A POST_public -j POST_public_allow
-A POST_public -j POST_public_post
-A PREROUTING_ZONES -i eno1 -g PRE_public
-A PREROUTING_ZONES -g PRE_public
-A PRE_public -j PRE_public_pre
-A PRE_public -j PRE_public_log
-A PRE_public -j PRE_public_deny
-A PRE_public -j PRE_public_allow
-A PRE_public -j PRE_public_post
COMMIT
# Completed on Fri Sep 11 07:58:24 2020
# Generated by iptables-save v1.8.4 on Fri Sep 11 07:58:24 2020
*mangle
:PREROUTING ACCEPT [78641:5937844]
:INPUT ACCEPT [78611:5935350]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [46644:3913664]
:POSTROUTING ACCEPT [46670:3916660]
:FORWARD_direct - [0:0]
:INPUT_direct - [0:0]
:OUTPUT_direct - [0:0]
:POSTROUTING_direct - [0:0]
:PREROUTING_ZONES - [0:0]
:PREROUTING_direct - [0:0]
:PRE_public - [0:0]
:PRE_public_allow - [0:0]
:PRE_public_deny - [0:0]
:PRE_public_log - [0:0]
:PRE_public_post - [0:0]
:PRE_public_pre - [0:0]
-A PREROUTING -j PREROUTING_direct
-A PREROUTING -j PREROUTING_ZONES
-A INPUT -j INPUT_direct
-A FORWARD -j FORWARD_direct
-A OUTPUT -j OUTPUT_direct
-A POSTROUTING -j POSTROUTING_direct
-A PREROUTING_ZONES -i eno1 -g PRE_public
-A PREROUTING_ZONES -g PRE_public
-A PRE_public -j PRE_public_pre
-A PRE_public -j PRE_public_log
-A PRE_public -j PRE_public_deny
-A PRE_public -j PRE_public_allow
-A PRE_public -j PRE_public_post
COMMIT
# Completed on Fri Sep 11 07:58:24 2020
# Generated by iptables-save v1.8.4 on Fri Sep 11 07:58:24 2020
*raw
:PREROUTING ACCEPT [78642:5937896]
:OUTPUT ACCEPT [46646:3914420]
:OUTPUT_direct - [0:0]
:PREROUTING_ZONES - [0:0]
:PREROUTING_direct - [0:0]
:PRE_public - [0:0]
:PRE_public_allow - [0:0]
:PRE_public_deny - [0:0]
:PRE_public_log - [0:0]
:PRE_public_post - [0:0]
:PRE_public_pre - [0:0]
-A PREROUTING -j PREROUTING_direct
-A PREROUTING -j PREROUTING_ZONES
-A OUTPUT -j OUTPUT_direct
-A PREROUTING_ZONES -i eno1 -g PRE_public
-A PREROUTING_ZONES -g PRE_public
-A PRE_public -j PRE_public_pre
-A PRE_public -j PRE_public_log
-A PRE_public -j PRE_public_deny
-A PRE_public -j PRE_public_allow
-A PRE_public -j PRE_public_post
COMMIT
# Completed on Fri Sep 11 07:58:24 2020
# Generated by iptables-save v1.8.4 on Fri Sep 11 07:58:24 2020
*security
:INPUT ACCEPT [19038:1906726]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [47400:3969196]
:FORWARD_direct - [0:0]
:INPUT_direct - [0:0]
:OUTPUT_direct - [0:0]
-A INPUT -j INPUT_direct
-A FORWARD -j FORWARD_direct
-A OUTPUT -j OUTPUT_direct
COMMIT
# Completed on Fri Sep 11 07:58:24 2020
# Generated by iptables-save v1.8.4 on Fri Sep 11 07:58:24 2020
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [30649:2765745]
:FORWARD_IN_ZONES - [0:0]
:FORWARD_OUT_ZONES - [0:0]
:FORWARD_direct - [0:0]
:FWDI_public - [0:0]
:FWDI_public_allow - [0:0]
:FWDI_public_deny - [0:0]
:FWDI_public_log - [0:0]
:FWDI_public_post - [0:0]
:FWDI_public_pre - [0:0]
:FWDO_public - [0:0]
:FWDO_public_allow - [0:0]
:FWDO_public_deny - [0:0]
:FWDO_public_log - [0:0]
:FWDO_public_post - [0:0]
:FWDO_public_pre - [0:0]
:INPUT_ZONES - [0:0]
:INPUT_direct - [0:0]
:IN_public - [0:0]
:IN_public_allow - [0:0]
:IN_public_deny - [0:0]
:IN_public_log - [0:0]
:IN_public_post - [0:0]
:IN_public_pre - [0:0]
:OUTPUT_direct - [0:0]
-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED,DNAT -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -j INPUT_direct
-A INPUT -j INPUT_ZONES
-A INPUT -m conntrack --ctstate INVALID -j DROP
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED,DNAT -j ACCEPT
-A FORWARD -i lo -j ACCEPT
-A FORWARD -j FORWARD_direct
-A FORWARD -j FORWARD_IN_ZONES
-A FORWARD -j FORWARD_OUT_ZONES
-A FORWARD -m conntrack --ctstate INVALID -j DROP
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
-A OUTPUT -o lo -j ACCEPT
-A OUTPUT -j OUTPUT_direct
-A FORWARD_IN_ZONES -i eno1 -g FWDI_public
-A FORWARD_IN_ZONES -g FWDI_public
-A FORWARD_OUT_ZONES -o eno1 -g FWDO_public
-A FORWARD_OUT_ZONES -g FWDO_public
-A FWDI_public -j FWDI_public_pre
-A FWDI_public -j FWDI_public_log
-A FWDI_public -j FWDI_public_deny
-A FWDI_public -j FWDI_public_allow
-A FWDI_public -j FWDI_public_post
-A FWDI_public -p icmp -j ACCEPT
-A FWDO_public -j FWDO_public_pre
-A FWDO_public -j FWDO_public_log
-A FWDO_public -j FWDO_public_deny
-A FWDO_public -j FWDO_public_allow
-A FWDO_public -j FWDO_public_post
-A INPUT_ZONES -i eno1 -g IN_public
-A INPUT_ZONES -g IN_public
-A IN_public -j IN_public_pre
-A IN_public -j IN_public_log
-A IN_public -j IN_public_deny
-A IN_public -j IN_public_allow
-A IN_public -j IN_public_post
-A IN_public -p icmp -j ACCEPT
-A IN_public_allow -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,UNTRACKED -j ACCEPT
COMMIT
# Completed on Fri Sep 11 07:58:24 2020

ssh 呼叫的圖像

我已經解決了這個問題，將 /etc/netplan/01-network-all.yaml 文件修改為以下內容：

network:
 version: 2
 renderer: networkd
 ethernets:
   eno1:
     addresses:
       - local ip/24
     gateway4: gateway ip
     nameservers:
       addresses:
         - 8.8.8.8
         - 8.8.4.4

之後我執行了以下命令：

sudo netplan --debug generate
sudo netplan apply
reboot

引用自：https://serverfault.com/questions/1033510