Invalid Packet Size

Dear users,


I have an issue, I have at home a Zywall USG100-PLUS and I'm trying to connect via SSL VPN, with SecuExtender, but is not working. Every time I receive this error: SSL tunnel receives a packet with invalid packet size.


Can someone help me with this issue ?


Thank you


Kind regards,

Alex

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All Replies

  • PeterUKPeterUK Member Posts: 341  Master Member
    edited August 17, 2019 4:06AM

    Are you using the newest SecuExtender and firmware 3.30(AACV.7)C0 ?

    Maybe try changing your MTU

    Or set your NIC to disable jumbo frame.

    Zyxel_Cooldia
  • zappuzappu Member Posts: 6

    Hello Peter,

    Sorry for my late reply. As a Firmware Package it shows me these:

    Boot module: 1.17

    Current version: V3.30(AACV.6)

    Do I need to have 3.30 (AACV.7) ? As for SecuExtender, yes I have the latest for SSL VPN.

    The part of MTU or NIC where I can find it ?


    Thank you

    Regards,

    Alex

  • PeterUKPeterUK Member Posts: 341  Master Member
    edited August 19, 2019 3:37AM

    In windows try this in CMD run as admin

    netsh interface ipv4 set interface "Local Area Connection" mtu=1492

    check here that its done

    if you run SecuExtender in your LAN to USG100-PLUS does it connect fine?

    Zyxel_Cooldiawarwickt
  • Zyxel_CooldiaZyxel_Cooldia Zyxel Official Agent Posts: 555  mod

    Hi @zappu

    Welcome to Zyxel Community. 😀

    The SeueExtender establish tunnel via virtual NIC ”Tap-Windows Adapter V9 for Zyxel SecuExtender”.

    Can you post your MTU value on that virtual NIC?


    Control panel > Network and Internet Connection > Network connection 

    click “configure ” to see the MTU value.


    warwickt
  • zappuzappu Member Posts: 6

    Dear guys,

    Here is the picture from my friend and it seems, it doesn't work also with modifications.


  • Zyxel_CooldiaZyxel_Cooldia Zyxel Official Agent Posts: 555  mod

    Hi @zappu ,

    Can you send me your configuration file via private message. 

    Let me have a quick lab test with your configuration file.

  • zappuzappu Member Posts: 6

    Hi @Zyxel_Cooldia,

    I sent you via private message the both files that I have in my router.

    Anyway yesterday night when I test it, I mean 1st I modified in my router on WAN from 1500 to 1400 and my Internet goes down and then I put it back to 1500. As for LAN when I modified from 1500 to 1400, 1392, 1370, 1300 or 1000, it works to connect to my LAN, but after 18 seconds he disconnected automatically and on my logs I received same error as the 1st one that I have put in my 1st message.

    I hope you can help me with this issue :).

    Thank you

    Regards,

    Alex

  • Zyxel_CooldiaZyxel_Cooldia Zyxel Official Agent Posts: 555  mod

    Hi @zappu ,

    As I remote check, the settings is good, and the tunnel uptime is around 20 minutes after I establish SSL VPN tunnel. Can you try to connect SecuExtender again with other pc?

  • zappuzappu Member Posts: 6

    Dear Chen,

    I made the tests and it seems is not working.

    Please find attached the pictures from my friend and also from my router.

    What we can do 😑?

    Thank you

    Regards,

    Alex


  • Zyxel_CooldiaZyxel_Cooldia Zyxel Official Agent Posts: 555  mod

    Hi @zappu ,

    It may need to remote check on your SecuExtender client, I will contact you via private message.

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