I have been using Openvpn for some time. I currently have it installed
OpenVPN 2.4.0 x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [PKCS11] [MH/PKTINFO] [AEAD] built on Jul 18 2017
on Debian 9 KVM.
Clients connect to the server with openwrt, openpli, etc. (mips). Everything works without problems. I started testing Debian 10 KVM and installed OpenVPN from the repository (ver. 2.4.7). From debian 9, I moved the /etc /openvpn directory to debian 10
Some clients connect to the OpenVPN server without any problems, but some cannot connect at all.
Wed Jan 27 06:22:44 2021 TCP connection established with [AF_INET]xx.34.xx.155:4196
Wed Jan 27 06:22:45 2021 xx.34.xx.155:4196 TCP connection established with [AF_INET]192.168.1.56:45654
Wed Jan 27 06:22:45 2021 TCP connection established with [AF_INET]xx.99.110.173:58054
Wed Jan 27 06:22:45 2021 xx.34.xx.155:4196 TLS: Initial packet from [AF_INET]xx.34.xx.155:4196, sid=7df63db9 5baf36f6
Wed Jan 27 06:22:45 2021 TCP connection established with [AF_INET]xx.99.56.195:56489
Wed Jan 27 06:22:45 2021 xx.34.xx.155:4196 TLS error: Unsupported protocol. This typically indicates that client and server have no common TLS version enabled. This can be caused by mismatched tls-version-min and tls-version-max options on client and server. If your OpenVPN client is between v2.3.6 and v2.3.2 try adding tls-version-min 1.0 to the client configuration to use TLS 1.0+ instead of TLS 1.0 only
Wed Jan 27 06:22:45 2021 xx.34.xx.155:4196 OpenSSL: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol
Wed Jan 27 06:22:45 2021 xx.34.xx.155:4196 TLS_ERROR: BIO read tls_read_plaintext error
Wed Jan 27 06:22:45 2021 xx.34.xx.155:4196 TLS Error: TLS object -> incoming plaintext read error
Wed Jan 27 06:22:45 2021 xx.34.xx.155:4196 TLS Error: TLS handshake failed
Wed Jan 27 06:22:45 2021 xx.34.xx.155:4196 Fatal TLS error (check_tls_errors_co), restarting
Wed Jan 27 06:22:45 2021 xx.34.xx.155:4196 SIGUSR1[soft,tls-error] received, client-instance restarting
Some clients that cannot connect to the OpenVPN server use
OpenVPN 2.3.2 mipsel-oe-linux-gnu [SSL (OpenSSL)] [LZO] [EPOLL] [MH] [IPv6] built on Oct 23 2017
I found some
information about my issue.I would like to know if it is enough to add this directive to client.conf
tls-version-min 1.0
Ideally, I would update with OpenVPN clients, but it's not that simple.
Thank You
