ANSWERED AEAD Decrypt Error: bad packet ID (may be a replay):

[blank90 3]

I have this repeating in my logs. What is the significance? Packet loss on this server? Currently connected to Imai in San Jose, CA, USA.

I read: "Generally, you can ignore this message, if it only happens once in a while."

[Staff 10691]

2 hours ago, blank90 said:

have this repeating in my logs. What is the significance? Packet loss on this server? Currently connected to Imai in San Jose, CA, USA.

Hello!

The most common causes are a "dirty" line and an MTU related problem. Less frequently it's a replay attack. Please try to get a stronger WiFi signal, change WiFi channel, test a different Ethernet cable, make sure that network interface driver and router firmware are both up to date. For the second cause try to adjust network interface MTU down to 1280 bytes if you use WireGuard, or add mssfix directive if you run OpenVPN (try for example mssfix 1280).

Kind regards
 

[blank90 3]

On 5/30/2024 at 2:12 AM, Staff said:

Hello!

The most common causes are a "dirty" line and an MTU related problem. Less frequently it's a replay attack. Please try to get a stronger WiFi signal, change WiFi channel, test a different Ethernet cable, make sure that network interface driver and router firmware are both up to date. For the second cause try to adjust network interface MTU down to 1280 bytes if you use WireGuard, or add mssfix directive if you run OpenVPN (try for example mssfix 1280).

Kind regards
 

Also, what happens if it is a replay attack? Could my credentials to accounts be compromised?

[Staff 10691]

8 hours ago, blank90 said:

Also, what happens if it is a replay attack? Could my credentials to accounts be compromised?

Hello!

No, they can't: OpenVPN and WireGuard are invulnerable to replay attacks in real life. Nevertheless a massive replay attack can dramatically slow down the VPN tunnel throughput because of the massive amount of packets that need to be dropped and re-sent.

Kind regards
 

[Air4141841 30]

before I moved to instances with opnsense I could mute the messages instead of it creating pages and pages and pages of logs on my router.
now I no longer have that ability as there is no advanced configuration area anymore.

I've opened a few tickets.   nothing suggested resolves this.      

--mute-replay-warnings

https://openvpn.net/community-resources/reference-manual-for-openvpn-2-5/

 

[Staff 10691]

@Air4141841

Hello!

By muting the entries you would hide the problem but wouldn't solve it. Try with mssfix 1280 directive. It will tell OpenVPN to split TCP packets inside the UDP tunnel larger than 1280 bytes; if the problem is related to MTU this directive alone can greatly mitigate or solve it altogether.

Kind regards