Objective:
- Dial-up IPsec VPN connection between two FortiGates.
- Using two ISP to establish VPN connections between each other for the same sites.
In this example, Port1 is used for DialupServer1(Primary) and Port5 used for DialupServer2 (Secondary). A similar setup is configured for DialupClient.
In this example, DialupServer is 10.185.0.0/20 and DialupClient is 10.162.0.0/20.
- Both tunnels should be active and redundancy or failover should be steered by the SD-WAN rule.
- The requirement is that, when DialupServer1 tunnel is down, traffic should routed via DialupServer2 tunnel. Eventually, when DialupServer1 is alive, traffic should be forwarded back via DialupServer1 tunnel which is selected by the SD-WAN rule.
Below are the configuration steps:
- Create a VPN overlay tunnel in SD-WAN for both dial-up server and dial-up client FortiGates.
The output should be as below:
- VPN settings:
DialupServer1 and DialupServer2 should be similar:
DialupClient1 and DialupClient2 should be similar:
- BGP routing:
Dial-up Server:
Dial-up Client:
- Create a default static route for SD-WAN/Overlay tunnel on the FortiGates at both ends.
- Create an address group for the phase2 selector in DialupServer1 & 2 VPN FortiGate.
The local address group includes the local network, DialupServer1 & 2 tunnel IP (with mask /32).
The remote address group includes the remote network, DialupClient1 & 2 tunnel IP (with mask /32).
Configure the same on the DialupClient1 and DialupClient2 FortiGate VPNs.
- SD-WAN rule:
Create an SD-WAN rule to steer the traffic on the FortiGates at both ends.
- VPN tunnel interface:
- Firewall Policy:
Create a firewall policy for the VPN tunnel in and out of FortiGate on both ends.
Final output:
Notes:
- There is an issue reported where tracert from the user machine shows the next hop as the secondary BGP neighbor IP address when the primary tunnel is coming back UP. However, traffic is still routed via the primary tunnel.
- There are no issues between FortiOS v6.4.x - v7.0.12, where tracert will show the primary neighbor as the next hop correctly when the primary tunnel is alive.
- This issue is observed in FortiOS v7.0.13 onwards.
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