ivan.f
Hello,
I was producing this behavior which have no explanation.
when I make a dump in eht1 interface I see the ip source UDP packets IP Phone is assigned to but if I make the dump from the tun0 interface ip source becomes public IP, the nat table iptables this empty, I have no masking rules.
PBX and phones are Panasonic brand.
I have performed more tests, for example, DNS queries that pass through the tunnel do not have this behavior. I have also installed an asterisk, and have connected a softphone across the tunnel and not suffer from this behavior.
I have the phone blocked ip Internet connection, so you have no way of knowing the public IP. I allow only access to the network across the tunnel, where the PBX is connected.
Any explanation?
tcpdump -i eth1 net 192.168.14.0/24
10:31:53.634628 IP phone.9301 > pbx.9300: UDP, length 105
10:32:01.635298 IP phone.9301 > pbx.9300: UDP, length 105
10:32:09.635982 IP phone.9301 > pbx.9300: UDP, length 105
10:32:14.137265 IP phone.9301 > pbx.9300: UDP, length 105
10:32:14.636366 IP phone.9301 > pbx.9300: UDP, length 105
10:32:15.636475 IP phone.9301 > pbx.9300: UDP, length 105
10:32:17.636610 IP phone.9301 > pbx.9300: UDP, length 105
10:32:21.636967 IP phone.9301 > pbx.9300: UDP, length 105
10:32:29.637599 IP phone.9301 > pbx.9300: UDP, length 105
10:32:37.638258 IP phone.9301 > pbx.9300: UDP, length 105
tcpdump -i tun0 net 192.168.14.0/24
10:31:53.634667 IP public.ip.9301 > pbx.9300: UDP, length 105
10:32:01.635335 IP public.ip.9301 > pbx.9300: UDP, length 105
10:32:09.636018 IP public.ip.9301 > pbx.9300: UDP, length 105
10:32:14.137298 IP public.ip.9301 > pbx.9300: UDP, length 105
10:32:14.636393 IP public.ip.9301 > pbx.9300: UDP, length 105
10:32:15.636515 IP public.ip.9301 > pbx.9300: UDP, length 105
10:32:17.636641 IP public.ip.9301 > pbx.9300: UDP, length 105
10:32:21.636996 IP public.ip.9301 > pbx.9300: UDP, length 105
10:32:29.637634 IP public.ip.9301 > pbx.9300: UDP, length 105
10:32:37.638302 IP public.ip.9301 > pbx.9300: UDP, length 105
ping work fine!
tcpdump -i tun0 icmp
10:42:11.569881 IP cpu002 > phone: ICMP echo request, id 1, seq 17, length 40
10:42:11.570655 IP phone > cpu002: ICMP echo reply, id 1, seq 17, length 40
10:42:12.570873 IP cpu002 > phone: ICMP echo request, id 1, seq 18, length 40
10:42:12.571640 IP phone > cpu002: ICMP echo reply, id 1, seq 18, length 40
10:42:13.571108 IP cpu002 > phone: ICMP echo request, id 1, seq 19, length 40
10:42:13.571874 IP phone > cpu002: ICMP echo reply, id 1, seq 19, length 40
