HMAC Authentication Errors (via VPN)

[p3hndrx]

Greetings---

I have a Nighthawk X4 (R7500), and have enabled the VPN Service per this article:
https://kb.netgear.com/25389/Enabling-VPN-service-on-a-Nighthawk-router-using-a-MAC-OS-computer

Everything connects fine, but I get the following errors:

2018-04-09 12:59:54 Authenticate/Decrypt packet error: packet HMAC authentication failed

2018-04-09 12:59:54 Authenticate/Decrypt packet error: packet HMAC authentication failed

(repeated)...

I am able to access resources on my local network, but the connection is VERY slow.
Services like RDP are impossible to use.

My config:
client
dev tap
proto udp
sndbuf 393216
rcvbuf 393216
;dev-node NETGEAR-VPN
remote xxxx.xxxxx.net12974
resolv-retry infinite
nobind
persist-key
persist-tun
ca ca.crt
cert client.crt
key client.key
;remote-cert-tls server
cipher AES-128-CBC
comp-lzo
verb 0

[p3hndrx · Accepted solution]

I resolved this by switching to TCP Mode and redownloading the openvpn config.

The biggest differences were:
client
dev tap
proto tcp
sndbuf 0
rcvbuf 0
[...]

[p3hndrx]

More info:

It looks like I get a connection and I am able to see UDP RW packets correctly.
I am able to connect to the router itself via http (e.g. 10.0.0.1), but it generates the HMAC authentication messages and moves VERY slowly.
I am able to connect to my local workstations via RDP, but it is very very slow.

For a test, I forwarded RDP ports and it moves very quickly/normally.
So it appears that there is something lost in the decryption? overhead?

[p3hndrx · Accepted solution]

I resolved this by switching to TCP Mode and redownloading the openvpn config.

The biggest differences were:
client
dev tap
proto tcp
sndbuf 0
rcvbuf 0
[...]