OpenVPN Connect IOS - setup with Asus (Merlin) OpenVPN Server on Router

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PC Pilot
OpenVpn Newbie
Posts: 2
Joined: Tue Apr 14, 2020 8:35 pm

OpenVPN Connect IOS - setup with Asus (Merlin) OpenVPN Server on Router

Post by PC Pilot » Tue Apr 14, 2020 9:14 pm

Hi to all,

I am trying to establish a connection from my iPhone 8 Plus (IOS 13.4.1) using OpenVPN Connect (V3.1.2 (3096)) with an OpenVPN Server setup on my Asus RT-AX88U router currently using Merlin's 384.14 firmware. So far all attempts to connect (in spite of numerous revisions to the settings) fails with the OpenVPN Connect log reporting Server poll timeout.

I am currently using the following OpenVPN Server settings:

VPN Server - OpenVPN

Basic Config

Server instance Server 1
Enable OpenVPN Server [ON]
VPN Details Advanced Settings

Advanced Settings

Interface Type TUN
Protocol UDP
Server Port 1184 (Default is: 1194)
Authorization Mode TLS
Keys and Certificates Edit (if necessary but certificate created by applying settings)
Username/Password Authentication
Yes Selected
No Unselected
Username/Password Auth. Only
Yes Unselected
No Selected
TLS control channel security (tls-auth/tls-crypt) Encrypt Channel
HMAC Authentication Default
VPN Subnet/Netmask 10.8.0.0 255.255.255.0
Advertise DNS to clients
Yes Selected
No Unselected
Cipher Negotiation Enable (with fallback)
Negotiable Ciphers AES-256-GCM:AES-128-GCM:AES-256-CBC:AES-128-CBC
Legacy/fallback cipher AES-128-GCM
Compression LZ0 Adaptive
Log verbosity 3
Manage Client-Specific Options
Yes Selected
No Unselected
Allow Client <-> Client
Yes Unselected
No Selected
Allow only specified clients
Yes Unselected
No Selected

Allowed Clients

Common Name (CN) (1) [BLANK]
Subnet (1) [BLANK]
Mask (1) [BLANK]
Push (1) [No Selection]

Custom Configuration

[NO ENTRIES RECORDED]

** From General Settings **

Username and Password (Max Limit: 32) (Router Username/Password)

Connection Status (1) Disconnected

Username (1) XXXXXXXXXXX (NB. Displays my Router Username accurately in text form)

Password (1) -

---------------------------------------------------------------------------------------------------------

The (obfuscated) OpenVPN Connect Log reports as follows:

2020-04-14 19:03:59 1

2020-04-14 19:03:59 ----- OpenVPN Start ----- OpenVPN core 3.git::f225fcd0 ios arm64 64-bit PT_PROXY built on Mar 5 2020 13:46:31

2020-04-14 19:03:59 OpenVPN core 3.git::f225fcd0 ios arm64 64-bit PT_PROXY built on Mar 5 2020 13:46:31

2020-04-14 19:03:59 Frame=512/2048/512 mssfix-ctrl=1250

2020-04-14 19:03:59 UNUSED OPTIONS
5 [ncp-ciphers] [AES-256-GCM:AES-128-GCM:AES-256-CBC:AES-128-CBC]
14 [resolv-retry] [infinite]
15 [nobind]

2020-04-14 19:03:59 EVENT: RESOLVE

2020-04-14 19:03:59 Contacting [81.xxx.xxx.xxx]:1184/UDP via UDP

2020-04-14 19:03:59 EVENT: WAIT

2020-04-14 19:03:59 Connecting to [host.xxxxxxxx.com]:1184 (81.xxx.xxx.xxx) via UDPv4

2020-04-14 19:04:09 Server poll timeout, trying next remote entry...

2020-04-14 19:04:09 EVENT: RECONNECTING

2020-04-14 19:04:09 EVENT: RESOLVE

2020-04-14 19:04:09 Contacting [81.xxx.xxx.xxx]:1184/UDP via UDP

2020-04-14 19:04:09 EVENT: WAIT

2020-04-14 19:04:09 Connecting to [host.xxxxxxxx.com]:1184 (81.xxx.xxx.xxx) via UDPv4

2020-04-14 19:04:20 Server poll timeout, trying next remote entry...

2020-04-14 19:04:20 EVENT: RECONNECTING

2020-04-14 19:04:20 EVENT: RESOLVE

2020-04-14 19:04:20 Contacting [81.xxx.xxx.xxx]:1184/UDP via UDP

2020-04-14 19:04:20 EVENT: WAIT

2020-04-14 19:04:20 Connecting to [host.xxxxxxxx.com]:1184 (81.xxx.xxx.xxx) via UDPv4

2020-04-14 19:04:29 EVENT: CONNECTION_TIMEOUT [ERR]

2020-04-14 19:04:29 Raw stats on disconnect:
BYTES_OUT : 406
PACKETS_OUT : 29
CONNECTION_TIMEOUT : 1
N_RECONNECT : 2

2020-04-14 19:04:29 Performance stats on disconnect:
CPU usage (microseconds): 52166
Network bytes per CPU second: 7782
Tunnel bytes per CPU second: 0

2020-04-14 19:04:29 EVENT: DISCONNECTED

2020-04-14 19:04:29 Raw stats on disconnect:
BYTES_OUT : 406
PACKETS_OUT : 29
CONNECTION_TIMEOUT : 1
N_RECONNECT : 2

2020-04-14 19:04:29 Performance stats on disconnect:
CPU usage (microseconds): 71375
Network bytes per CPU second: 5688
Tunnel bytes per CPU second: 0

--------------------------------------------------------------------------------------

Can anybody offer assistance as to what settings are required or indeed any thoughts of steps I should take to resolve.

Many thanks,

PC Pilot.

PC Pilot
OpenVpn Newbie
Posts: 2
Joined: Tue Apr 14, 2020 8:35 pm

Re: OpenVPN Connect IOS - setup with Asus (Merlin) OpenVPN Server on Router

Post by PC Pilot » Tue Apr 14, 2020 9:27 pm

Quick update....

Have established a connection now by changing the protocol from UDP to TCP.... having been advised previously that UDP was best option :)

Any thoughts? Does IOS require TCP ??

User avatar
TinCanTech
OpenVPN Protagonist
Posts: 7177
Joined: Fri Jun 03, 2016 1:17 pm

Re: OpenVPN Connect IOS - setup with Asus (Merlin) OpenVPN Server on Router

Post by TinCanTech » Tue Apr 14, 2020 9:36 pm

Check your server log ..

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