I have Cisco1801 connected to 2 ISPs. Each ISP connected with real IP address. Each WAN interface have associated VTI. Main role of Cisco1801 is IPSec hub for many ipsec clients to make secure link between subnets. Each ipsec client creates 2 IPSec tunnels: first via ISP1 and second via ISP2.
Cicso VTI1 device
Cisco VTI2 device
After ipsec is established we have two new interfaces Virtual-Access1 and Virtual-Access2 Also we have two new routes for subnets 192.168.40.0/24 and 192.168.140.0/24.
192.168.1.1 and 192.168.2.1 are addresses of Vlan2 interface.
If default gateway is set up all works perfectly. If default gateway is removed intercommunications between subnets are lost.
Could I use ipsec without default gateway?