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VPN zone traffic to LAN zone getting dropped

ArunGupta

SFOS 16.05.6 MR-6

Migrating from UTM 9 to XG.

I have created a L2TP VPN from my Android phone to XG. The VPN connects but all the traffic going to LAN zone is getting dropped. I have created a firewall rule to allow all traffic from VPN zone to LAN zone but the firewall logs still show that traffic is being dropped. My understanding is that the IP subnet that I define in VPN settings, automatically gets added to the VPN zone, so the rule should work. Please advise on how to fix.

Thanks,

Arun



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  • 0 in reply to lferrara

    Thanks for quick reply. Here is the info:

     

    L2TP (Remote Access)
    Name: MyVPN
    Description:
    Policy: DefaultL2TP
    Action on VPN Restart: Respond Only

    Authentication Type: Preshared key
    Preshared Key: <preshared key string>

    Local WAN Port: Port2 - <My Public IP is automatically filled>
    Local ID: I did not enter any local ID

    Remote Host: *
    Allow NAT Traversal: Checked
    Remote LAN Network: Any
    Remote ID: I did not enter any remote ID

    Local Port: 1701
    Remote Port: *

    Disconnect when tunnel is idle: Enabled
    Idle session time interval: 600

    ===================
    Show VPN Setiings -> L2TP
    Enable L2TP box checked

    Assign IP from: 10.242.1.0 - 10.242.1.255
    Box unchecked: Allow leasing IP address from RADIUS server

    Primary DNS server: Other 192.168.250.1 (This is the XG firewall LAN address)

    Show Members: arun_l2tp_vpn and Open Group
    ===================
    Rule Name: VPN to LAN

    Source Zones: VPN
    Source Networks and Devices: Any
    During Scheduled Time: All the time

    Destination Zones: LAN
    Destination Networks: Any
    Services: Any

    Match known Users: unchecked

    Malware scanning: all boxes unchecked

    Intrusion Prevention: None
    Traffic Shaping Policy: None
    Web Policy: None
    Application Control: None

    Minimum Source HB Permitted: No restriction
    Mimimum Destination HB permitted: No restriction

    Rewrite source address (Masquerading): Checked
    Use Gateway Specific Default NAT Policy: Unchecked
    Use Outbound Address: MASQ
    Primary Gateway: None
    DSCP Marking: Select DSCP Marking (none selected)

    In the NAT settings, I have tried various combinations of options, but none worked.

    I don't know how to get to the logs, but in Log Viewer, I select Firewall Logs from drop down list and then filter on ppp0 as In Interface.
    This is typically what I see. The DNS requests are being denied.

    2017-07-24 15:35:39 Local ACL Denied arun_l2tp_vpn 0 ppp0 - 10.242.1.1 :UDP (1511) 192.168.250.1 :UDP (53) 02002 Open PCAP


  • 0 in reply to ArunGupta

    Arun,

    thanks for sharing info. UPD 53 is DNS requests traffic. Go to VPN > Show VPN Settings > L2TP and fill DNS with your internal DNS server (if you need to access internal resources by name).

    If it is not enough, create a reverse rule LAN TO VPN.

    Let us know

    Thanks

  • 0 in reply to lferrara

    Finally it is working. I had taken screen captures of UTM settings. Following those, here is what I had to do to get everything working:

    a) Create a rule for allowing VPN connected phone to access internet and other common services

    Source: VPN, Any host

    Destination: WAN, Any host

    Services; DNS, HTTP, HTTPS, NTP, Gmail Ports and so on.

    Rewrite source address (Masquerading): checked

    Use Gateway Specific Default NAT Policy: checked

    b) Create a rule for allowing VPN to access LAN:

    Source; VPN, Any host

    Desination: LAN, Any host

    Service: Any

    Rewrite source address (Masquerading): checked

    Use Gateway Specific Default NAT Policy: checked

     c) In VPN->Show VPN Settings, defined the DNS server as the server in my LAN zone (I run my own DNS server). This server is defined as the DNS server in XG DNS settings also.

    Now everything is working. When phone is connected to VPN, I can ping hosts on my LAN. I have not tested RDP/SSH connectivity, but I am sure it will work. It seems that no matter what I do, XG does not allow any kind of access to its own IP (not even ping) from the phone when connected via VPN. Since I was trying to use the XG IP address as DNS server in the hope that it will forward queries to my LAN DNS server, the DNS access was being denied. It just would not have worked.

    If I disable any of the above firewall rules, internet access on the phone stops working when connected to VPN. I think this is because I am using DNS server in the LAN zone, so if VPN to LAN rule is disabled, the VPN connected device cannot reach DNS server. If a public DNS server like 8.8.8.8 is configured in VPN settings, then there is no need for the VPN to LAN zone rule.

    Thanks for all your help.

    Arun