WARNING: Compression for receiving enabled

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Hansola
OpenVpn Newbie
Posts: 1
Joined: Mon Dec 27, 2021 10:04 am

WARNING: Compression for receiving enabled

Post by Hansola » Mon Dec 27, 2021 10:06 am

Good day

When i want to connect is have this Warning
Please can you help me

2021-12-27 10:57:10 WARNING: Compression for receiving enabled. Compression has been used in the past to break encryption. Sent packets are not compressed unless "allow-compression yes" is also set.
2021-12-27 10:57:10 DEPRECATED OPTION: --cipher set to 'AES-256-CBC' but missing in --data-ciphers (AES-256-GCM:AES-128-GCM). Future OpenVPN version will ignore --cipher for cipher negotiations. Add 'AES-256-CBC' to --data-ciphers or change --cipher 'AES-256-CBC' to --data-ciphers-fallback 'AES-256-CBC' to silence this warning.
2021-12-27 10:57:10 OpenVPN 2.5.4 Windows-MSVC [SSL (OpenSSL)] [LZO] [LZ4] [PKCS11] [AEAD] built on Oct 20 2021
2021-12-27 10:57:10 Windows version 10.0 (Windows 10 or greater) 64bit
2021-12-27 10:57:10 library versions: OpenSSL 1.1.1l 24 Aug 2021, LZO 2.10
2021-12-27 10:57:10 TCP/UDP: Preserving recently used remote address: [AF_INET]144.76.139.188:1196
2021-12-27 10:57:10 UDP link local: (not bound)
2021-12-27 10:57:10 UDP link remote: [AF_INET]144.76.139.188:1196
2021-12-27 10:58:10 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
2021-12-27 10:58:10 TLS Error: TLS handshake failed
2021-12-27 10:58:10 SIGUSR1[soft,tls-error] received, process restarting
2021-12-27 10:58:15 TCP/UDP: Preserving recently used remote address: [AF_INET]144.76.139.188:1196
2021-12-27 10:58:15 UDP link local: (not bound)
2021-12-27 10:58:15 UDP link remote: [AF_INET]144.76.139.188:1196
2021-12-27 10:59:15 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
2021-12-27 10:59:15 TLS Error: TLS handshake failed
2021-12-27 10:59:15 SIGUSR1[soft,tls-error] received, process restarting
2021-12-27 10:59:20 TCP/UDP: Preserving recently used remote address: [AF_INET]144.76.139.188:1196
2021-12-27 10:59:20 UDP link local: (not bound)
2021-12-27 10:59:20 UDP link remote: [AF_INET]144.76.139.188:1196
2021-12-27 11:00:20 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
2021-12-27 11:00:20 TLS Error: TLS handshake failed
2021-12-27 11:00:20 SIGUSR1[soft,tls-error] received, process restarting
2021-12-27 11:00:25 TCP/UDP: Preserving recently used remote address: [AF_INET]144.76.139.188:1196
2021-12-27 11:00:25 UDP link local: (not bound)
2021-12-27 11:00:25 UDP link remote: [AF_INET]144.76.139.188:1196
2021-12-27 11:01:06 SIGTERM received, sending exit notification to peer
2021-12-27 11:01:07 SIGTERM[soft,exit-with-notification] received, process exiting

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openvpn_inc
OpenVPN Inc.
Posts: 658
Joined: Tue Feb 16, 2021 10:41 am

Re: WARNING: Compression for receiving enabled

Post by openvpn_inc » Thu Jan 06, 2022 10:01 pm

Hello Hansola,

Ever since the Voracle vulnerability report (see https://openvpn.net/security-advisory/t ... erability/) we are discouraging the use of compression with OpenVPN.

What you see here is the result of a server that has compression enabled, but the client has it disabled. This means that the information sent from the server to the client is compressed, because that is what the server is configured to do. And the data sent from the client to the server is not compressed, because that is what the client is configured to do. Of course the client cannot change the server's behavior, but it can at least warn you about this and refuse to compound the problem by adding compression on the client side as well.

To solve this check into the configuration of the server and disable compression there. Then both sides will stop using compression.

Kind regards,
Johan
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Answers provided by OpenVPN Inc. staff members here are provided on a voluntary best-effort basis, and no rights can be claimed on the basis of answers posted in this public forum. If you wish to get official support from OpenVPN Inc. please use the official support ticket system: https://openvpn.net/support

jAkejaws99
OpenVpn Newbie
Posts: 1
Joined: Sat Jan 22, 2022 12:19 pm

Re: WARNING: Compression for receiving enabled

Post by jAkejaws99 » Sat Jan 22, 2022 12:21 pm

I have the same issue, how would I go about checking into the configuration of the server to disable compression there ? thank you...

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