zhamm I'm running an openvpn server that I can successfully connect to and route through using IPV4. However, I have some cellular network clients (Apple iOS) that insist on connecting via IPV6, which I don't want. The iOS devices are getting both IPV4 and IPV6 addresses from the cellular provider, but the openvpn connect client wants to use IPV6, even when told not to. The same iOS device will connect successfully on IPV4 if on WiFi LAN but will use IPV6 when on LTE. How do I completely disable IPV6 in OpenVPN? Server: OpenVPN 2.4 (Ubuntu repo version) Client: OpenVPN 2.5.3 (iOSversion) 1. I have tried configuring the server and client both with "proto udp4", but the connection is still IPV6 on these devices. 2. I've disabled IPV6 on bootup in the OS kernel (Ubuntu 20.04) and rebooted. There are no IPV6 addresses for eth0 or lo, but tun0 still seems to generate an IPV6 address when connecting via cellular. 3. Server.conf: port 1194 proto udp4 dev tun ca ca.crt cert server.crt key server.key dh dh.pem auth SHA512 tls-crypt tc.key topology subnet server 10.8.0.0 255.255.255.0 push "redirect-gateway def1" ifconfig-pool-persist ipp.txt push "dhcp-option DNS 1.1.1.1" push "dhcp-option DNS 1.0.0.1" keepalive 10 120 cipher AES-256-CBC user nobody group nogroup persist-key persist-tun verb 3 crl-verify crl.pem explicit-exit-notify 4. client.conf client dev tun proto udp4 remote xxx.xxx.xxx.xxx 1194 udp4 resolv-retry infinite nobind persist-key persist-tun remote-cert-tls server auth SHA512 cipher AES-256-CBC ignore-unknown-option block-outside-dns block-outside-dns verb 3
eenoch Transport works over WiFi and fails over 5G (iPhone as client) by merely forcing the phone to use 5G.
TinCanTech That has absolutely nothing to do with the original post here. Please start your own thread.
zhamm Yeah, except I have evidence otherwise. iPad client constantly connects as IPV6 even though I have no IPV6 enabled on server at kernel level. Very weird.
TinCanTech I expect, if you post your logs, we will find something .. https://forums.openvpn.net/viewtopic.php?f=30&t=22603
TinCanTech zhamm wrote How do I completely disable IPV6 in OpenVPN? Disable it in your server OS. OpenVPN always uses v6, if it can.
