-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Tuesday, 2017-12-19 at 13:13 +0100, jdd@dodin.org wrote:
Le 19/12/2017 à 11:38, Carlos E. R. a écrit :
You are both forgetting that both the OP and him mom router's external addresses are on a 10.*.*.* IP range, and probably a different one each.
if they can reach the net, why bother? They need some external relay, I don't know if dyndns can do that.
A service like dyndns works even if the IP changes, but not in this case, because the routers do not have routable public addreses.
if they can send mails, of course there is one somewhere (a gateway), looking at mail header will tell which
No use.
The can't even ping one another.
my own adress is 192.168.1.40, of course you can't ping me
Well, that's precissely the problem. We can not ping an address like 10.x.y.z, either. Both routers can not ping one another. 192.168.*.* ---[router]--- 10.a.b.c ---[ISP 1]--- public intrnt ---| (nat) (nat) | prvte adrss prvte adrss | | 192.168.*.* ---[router]--- 10.a.b.c ---[ISP 2]--- public intrnt ---| (nat) (nat) You can not address a ping to the external interface of the routers, because the routers themselves are in a private network, and the ISP is doing NAT. The ISP does not have enough public internet addresses to give them. The only thing you can reach is the Gateway at each ISP, no further. - -- Cheers, Carlos E. R. (from openSUSE 42.2 x86_64 "Malachite" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAlo5CwEACgkQtTMYHG2NR9WMWACeJ1jVJGQv+gaXBnCprNmykRpC 1NwAn3g5EmaOvu5enE2R6GzzUN6PI3xV =zhac -----END PGP SIGNATURE-----