Confusing about default gateway with multiple FIB.

[epopen]

Hi All

I am using VIMAGE(vnet) + netgraph(4) to build independence two jail(8) as follows.

Here, NIC ng_vimage0 using jail (IP range: 10.0.2.0~10.0.3.254) to access with host and internet, FIB=1

ng_vimage0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1492
        options=28<VLAN_MTU,JUMBO_MTU>
        ether 02:ac:95:e3:83:d2
        hwaddr 58:9c:fc:10:8a:17
        inet 10.0.3.254 netmask 0xfffffe00 broadcast 10.0.3.255
        fib: 1
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
        nd6 options=61<PERFORMNUD,AUTO_LINKLOCAL,NO_RADR>

Host side, NIC ng0 using host access internet by PPPoE (Dynamic IPv4) using net/mpd5

ng0: flags=10088d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1492
        options=0
        inet 220.132.60.27 --> 168.95.98.254 netmask 0xffffffff
        nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>

Next: host route table @ FIB=0

Internet:
Destination        Gateway            Flags         Netif Expire
default            168.95.98.254      UGS             ng0
10.0.2.0/23        link#6             US       ng_vimage0
127.0.0.1          link#2             UH              lo0
168.95.98.254      link#5             UH              ng0
220.132.60.27      link#2             UHS             lo0

And For jail route table @ FIB=1

Routing tables (fib: 1)

Internet:
Destination        Gateway            Flags         Netif Expire
default            link#5             US              ng0
10.0.2.0/23        link#6             U        ng_vimage0
10.0.3.254         link#2             UHS             lo0
127.0.0.1          link#2             UHS             lo0

(link#2 = lo0, link#5 = ng0 and link#6 = ng_vimage0)

The solution workable, but I confuing...
In jail route table @ FIB=1, default gateway = ng0 is correct?
(Because correct method I imagine it is that the default gateway is ng_vimage0,
and whether accessing the internet or the host from jail, it is routed through the system only (routing to ng0 when accessing the internet)
But I know I'm missing some key, so my imagination untenable).

If my current solution and imagine is incorrectly, would you can help to correct?

Thanks all very much.