Ubuntu
兩個 Raspberry PI 之間無法訪問目標主機
我有一個帶有樹莓派的臨時 IPv4 網路。現在這些節點彼此相鄰，每當我嘗試從 10.0.0.4 ping 到 10.0.0.6 時，這就是輸出。
PING 10.0.0.6 (10.0.0.6) 56(84) bytes of data. From 10.0.0.4 icmp_seq=1 Destination Host Unreachable From 10.0.0.4 icmp_seq=2 Destination Host Unreachable From 10.0.0.4 icmp_seq=3 Destination Host Unreachable兩個設備上的路由似乎都很好，這些是它們的 iwconfig、路由、arp 輸出：
在 10.0.0.4
pi@pi-raspberry4:~$ route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.1.254 0.0.0.0 UG 0 0 0 wdongle 10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 wboard 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 wboard 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 wdongle pi@pi-raspberry4:~$ arp -n Address HWtype HWaddress Flags Mask Iface 10.0.0.1 (incomplete) wboard 192.168.1.7 ether 28:39:26:c6:2e:af C wdongle 10.0.0.6 (incomplete) wboard 10.0.0.2 (incomplete) wboard 10.0.0.16 (incomplete) wboard 192.168.1.254 ether cc:7b:35:0d:7c:f8 C wdongle 10.0.0.15 (incomplete) wboard 10.0.0.12 (incomplete) wboard pi@pi-raspberry4:~$ iwconfig wdongle IEEE 802.11bgn ESSID:"tplinktest" Nickname:"<WIFI@REALTEK>" Mode:Managed Frequency:2.412 GHz Access Point: 14:CC:20:64:C7:10 Bit Rate:300 Mb/s Sensitivity:0/0 Retry:off RTS thr:off Fragment thr:off Power Management:off Link Quality=98/100 Signal level=64/100 Noise level=0/100 Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 lo no wireless extensions. wboard IEEE 802.11bgn ESSID:"RPiAdHocNetwork" Mode:Ad-Hoc Frequency:2.437 GHz Cell: 9A:29:92:92:6B:6C Tx-Power=31 dBm Retry short limit:7 RTS thr=1 B Fragment thr:off Power Management:on eth0 no wireless extensions. ip6tnl0 no wireless extensions.在 10.0.0.6
pi@pi-raspberry6:/etc$ route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.1.254 0.0.0.0 UG 0 0 0 wdongle 0.0.0.0 0.0.0.0 0.0.0.0 U 1002 0 0 eth0 10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 wboard 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 wboard 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 wdongle pi@pi-raspberry6:/etc$ arp -n Address HWtype HWaddress Flags Mask Iface 10.0.0.2 ether b8:27:eb:c6:8b:41 C wboard 192.168.1.254 ether cc:7b:35:0d:7c:f8 C wdongle 10.0.0.1 (incomplete) wboard 10.0.0.15 (incomplete) wboard 10.0.0.4 (incomplete) wboard 192.168.1.7 ether 28:39:26:c6:2e:af C wdongle pi@pi-raspberry6:/etc$ iwconfig wdongle IEEE 802.11bgn ESSID:"tplinktest" Nickname:"<WIFI@REALTEK>" Mode:Managed Frequency:2.412 GHz Access Point: 14:CC:20:64:C7:10 Bit Rate:300 Mb/s Sensitivity:0/0 Retry:off RTS thr:off Fragment thr:off Power Management:off Link Quality=100/100 Signal level=75/100 Noise level=0/100 Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0 lo no wireless extensions. wboard IEEE 802.11bgn ESSID:"RPiAdHocNetwork" Mode:Ad-Hoc Frequency:2.437 GHz Cell: 9A:29:92:92:6B:6C Tx-Power=31 dBm Retry short limit:7 RTS thr=1 B Fragment thr:off Power Management:on eth0 no wireless extensions. ip6tnl0 no wireless extensions.**我的問題：**可能是什麼原因造成的，如何解決？（除非它的硬體有問題）
注意：我的網路目前由 4 個樹莓派組成（其中一個是 3B+ 其餘的 3B）。它們中的每一個都通過闆卡 NIC 在 ad-hoc 網路中，並通過外部加密狗在我的家庭網路中。節點 10.0.0.4 -6 - 15 正在執行 Ubuntu 16.04.4 LTS，節點 10.0.0.2 可能有 rpi 的 NOOBS 發行版（我沒有找到 lsb_release）
似乎相互互動的唯一節點是 10.0.0.2 和 10.0.0.6。以前我正在執行一些 iperf 實驗，它們每個都傳輸了大約 1 Gb 的數據，但突然有些節點消失並且無法訪問（即 10.0.0.4 和 10.0.0.15）
原來問題是sshguard
我不知道 sshguard 正在執行並且在覆盆子之間進行了一些失敗的嘗試。在失敗的登錄嘗試日誌中存在這一行：
Blocking 192.168.1.7:4 for >630secs: 40 danger in 4 attacks over 2 seconds (all: 40d in 1 abuses over 2s)sshguard 似乎阻止了來自可疑攻擊者的所有 ipv4 流量，結果我是攻擊者