VPN KIE v1 and IKE v2 - MTU

DanDR

Hi

I have 2 conections VPN

1. IKEv1 (Microsoft Client) to Zyxel USG 500 - working fine
2. IKE v2 (Secu Extender VPN) to Zyxel USG 500 (the same network, Leptop and Zyxel USG 500)

And if i use VPN IKE v2 - i use RDP and i'm getting freezing all the time

on IKEv1 : ping 10.0.0.10 -f -l 1300 - is ok

on IKEv2 ping 10.0.0.10 -f -l 1300 Packet need to be fragmented but DF set.

I need information what to set on USG 500 or secuExtender VPN

(changing on VPN IKEv2 general setiings MSS Adjusment dosn't work) (I checked: AUTO, Custome size 1460, 1260)

Zyxel_Tina

Hi @DanDR,

Welcome to the Zyxel Community!

To better understand the issue, could you please help us confirm the following information?

1. Could you confirm whether the device is a USG FLEX 500, and share the firmware is currently running?
2. Regarding “freezing all the time”, could you describe what exactly happens? For example, does the RDP screen temporarily stop responding, become unresponsive until the connection recovers, or does the RDP session disconnect?
3. For the IKEv2 test, could you also let us know what result you get if running ping 10.0.0.10 without the additional -f -l 1300 parameter?

As we're trying to reproduce the situation you've encountered, this information will help us better understand the behavior and investigate the issue further. Thank you.

DanDR

The main problem is betwin IKEv1 and IKEv2,

Pinging without breaking.

Freezing is ,in RDP mosue ist stoped for while, 5 seckond is working fine and is freezein for a while . Pingin is on without problems.

I had a coversation with zyxell AI, and the problem is MTU (wan setiings), I had 1500 AI suggested to lower it to 1360 - but it didnt work.

and this setings VPN dint work as well

I think the problem is in Secu extender VPN -