Re: Question on default route
If you ran "flow debug", you would see errors and dropped packets due to "asymmetric route". The dialup vpn traffic comes in at port1 and tries going out through port10 based on your 0/0 route, which is not allowed by default.
Instead, what you can do is to set two default routes but different "priority" numbers. When you create the default route toward port 10, you didn't specified priority so it got '0'. You can configure another default route but higher priority number, like '10'. The higher the number is, the lower the priority is.
Then when internal users/devices generate traffic (sessions) toward the internet, it follows priority 0 default route. But return packets for the dialup vpn would go back to where the session was initiated from, which is port1 as long as the low priority (10) default route exist. The routing table would look like below. This is from one of our 1500D's vdom, which is doing exactly what you want to do.
xxx-fg1 (vdom-name1) # get router info routing-t all
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default
S* 0.0.0.0/0 [10/0] via 220.127.116.11, vlanxxxx-to-MPLS, [0/50] <- priority 0, another FW is in this direction
[10/0] via 18.104.22.168, vlan-on-vdomlink-to-INET, [10/50] <- priority 10, VPNs come from this interface