Cannot connect VPN IKEv2 to usg 100

Franz94370

I have configurate a IKEv2 VPN connection but each time i cannot connect and i saw this error message in the log

1	2024-10-17 07:55:12	warn	ADP	Rule_id:1 from WAN to Any, [type:UDP-Decoder(74)] oversize-len Action:Drop Packet [count=3]

V5.39(ABUH.0) / 2024-08-22 06:21:11

Can you help me ?

Best regards

Zyxel_Melen

Hi @Franz94370,

This is more likely due to the other side of the IKEv2 VPN sending over-size-length packets. What is the device that connects to USG FLEX 100? If it is site-to-site VPN, are the VPN configurations on both the routers/firewalls the same? (MSS)

In addition, if this device is trusted, you can set the ADP allow list to bypass the traffic. The rules below screenshot an example, you might need to adjust to fit your network.

Hope it helps.