I ran tcpdump on both the tun0 interface on the Linux host and the ethernet interface. Here are my findings:
tun0:
jnos@jnos:~$ tcpdump -ttttnnr tun0.pcap reading from file tun0.pcap, link-type RAW (Raw IP) 2021-08-03 07:20:59.480853 IP 192.168.3.2 > 70.30.145.159: IP 44.124.1.18 > 44.135.92.10: ICMP echo request, id 132, seq 0, length 12 (ipip-proto-4) jnos@jnos:~$
enp0s3 (ethernet interface):
tcpdump -ttttnnr enp0s3.pcap reading from file enp0s3.pcap, link-type EN10MB (Ethernet) 2021-08-03 07:27:07.539858 IP 192.168.2.109.22 > 68.230.83.177.52286: Flags [P.], seq 960163137:960163181, ack 1484797025, win 501, options [nop,nop,TS val 2519792167 ecr 101725450$ 2021-08-03 07:27:07.540185 IP 192.168.2.109.22 > 68.230.83.177.52286: Flags [P.], seq 44:152, ack 1, win 501, options [nop,nop,TS val 2519792168 ecr 1017254502], length 108 2021-08-03 07:27:07.540474 IP 192.168.2.109.22 > 68.230.83.177.52286: Flags [P.], seq 152:188, ack 1, win 501, options [nop,nop,TS val 2519792168 ecr 1017254502], length 36 2021-08-03 07:27:07.545856 IP 68.230.83.177.52286 > 192.168.2.109.22: Flags [.], ack 0, win 4094, options [nop,nop,TS val 1017254529 ecr 2519792149], length 0 2021-08-03 07:27:07.563693 IP 68.230.83.177.52286 > 192.168.2.109.22: Flags [.], ack 44, win 4094, options [nop,nop,TS val 1017254544 ecr 2519792167], length 0 2021-08-03 07:27:07.569058 IP 68.230.83.177.52286 > 192.168.2.109.22: Flags [.], ack 152, win 4092, options [nop,nop,TS val 1017254548 ecr 2519792168], length 0 2021-08-03 07:27:07.569074 IP 68.230.83.177.52286 > 192.168.2.109.22: Flags [.], ack 188, win 4094, options [nop,nop,TS val 1017254548 ecr 2519792168], length 0 2021-08-03 07:27:09.924559 IP 68.230.83.177.52388 > 192.168.2.109.22: Flags [P.], seq 3618295632:3618295668, ack 3618018734, win 4096, options [nop,nop,TS val 1017256892 ecr 251978$ 2021-08-03 07:27:09.925664 IP 192.168.2.109.22 > 68.230.83.177.52388: Flags [P.], seq 1:237, ack 36, win 501, options [nop,nop,TS val 2519794553 ecr 1017256892], length 236 2021-08-03 07:27:09.946944 IP 68.230.83.177.52388 > 192.168.2.109.22: Flags [.], ack 237, win 4088, options [nop,nop,TS val 1017256916 ecr 2519794553], length 0 2021-08-03 07:27:10.692162 IP 68.230.83.177.52388 > 192.168.2.109.22: Flags [P.], seq 36:80, ack 237, win 4096, options [nop,nop,TS val 1017257656 ecr 2519794553], length 44 2021-08-03 07:27:10.692776 IP 192.168.2.109.22 > 68.230.83.177.52388: Flags [P.], seq 237:313, ack 80, win 501, options [nop,nop,TS val 2519795320 ecr 1017257656], length 76 2021-08-03 07:27:10.711861 IP 68.230.83.177.52388 > 192.168.2.109.22: Flags [.], ack 313, win 4093, options [nop,nop,TS val 1017257678 ecr 2519795320], length 0 2021-08-03 07:27:11.183381 IP 68.230.83.177.52388 > 192.168.2.109.22: Flags [P.], seq 80:116, ack 313, win 4096, options [nop,nop,TS val 1017258142 ecr 2519795320], length 36 2021-08-03 07:27:11.184038 IP 192.168.2.109 > 70.30.145.159: IP 44.124.1.18 > 44.135.92.10: ICMP echo request, id 132, seq 0, length 12 (ipip-proto-4) 2021-08-03 07:27:11.184639 IP 192.168.2.109.22 > 68.230.83.177.52388: Flags [P.], seq 313:573, ack 116, win 501, options [nop,nop,TS val 2519795812 ecr 1017258142], length 260 2021-08-03 07:27:11.210903 IP 68.230.83.177.52388 > 192.168.2.109.22: Flags [.], ack 573, win 4087, options [nop,nop,TS val 1017258167 ecr 2519795812], length 0 jnos@jnos:~$
I sampled 44.135.92.10 and I can see the ICMP request goes out the tun0 and the enp3s0 interface. My iptables NAT is set to allow all traffic:
Chain POSTROUTING (policy ACCEPT) target prot opt source destination MASQUERADE all -- anywhere anywhere jnos@jnos:~$
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‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Thursday, August 12th, 2021 at 11:48 PM, Boudewijn (Bob) Tenty via 44Net 44net@mailman.ampr.org wrote:
Monitor with tcpdump in Linux to see what happens, like or it is leaving the right interface as IPIP packet,
responses, etc.
Bob VE3TOK
On 2021-08-12 07:09, debiani386 via 44Net wrote:
Is there anything else that I am missing here? I am still not able to ping any 44net nodes from within jnos.
Is there any more information I can provide that would be helpful here?
de KG7UJH
Christopher Kelley
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