Trying to setup multiple default routes between two N4064F at two different locations

Office has N4064F layer 3 setup with default gateway to the firewall on VLAN10 to the Internet

Datacenter has N4064F layer 3 setup with default gateway to the firewall on VLAN120 to the Internet

Recently added a PTP Fiber connection between Office and Datacenter on Port 10 with VLAN1051

I then setup static routes so that all LAN data is routed over the Fiber and that's working fine, before it was all done over site-site IPSec tunnels over the firewalls

I am trying to setup a backup default route for the internet to go out the Fiber and not the DIA at the office and I am having trouble

I tried to change the Office switch default route to point to 0.0.0.0 0.0.0.0 172.16.120.3 (which is the datacenter's default route) but this is wrong

 

Office N4064F

Default Gateway is 172.16.10.3
S *0.0.0.0/0 [1/0] via 172.16.10.3, 04h:45m:02s, Vl10
C *10.0.51.0/30 [0/0] directly connected, Vl1051
C *172.16.10.0/23 [0/0] directly connected, Vl10
C *172.16.14.0/23 [0/0] directly connected, Vl14
C *172.16.18.0/23 [0/0] directly connected, Vl18
C *172.16.22.0/23 [0/0] directly connected, Vl22
C *172.16.26.0/23 [0/0] directly connected, Vl26
C *172.16.30.0/23 [0/0] directly connected, Vl30
C *172.16.34.0/23 [0/0] directly connected, Vl34
S *172.16.120.0/23 [1/0] via 10.0.51.2, Vl1051

system jumbo mtu 9216
ip http timeout-policy idle 300 life 86400
no ip redirects
ip routing
ip helper-address 172.16.10.13 dhcp
ip helper-address 172.16.10.14 dhcp
interface vlan 10
ip address 172.16.10.1 255.255.254.0
exit
interface vlan 14
ip address 172.16.14.1 255.255.254.0
ip helper-address 172.16.10.13 dhcp
ip helper-address 172.16.10.14 dhcp
exit
interface vlan 18
ip address 172.16.18.1 255.255.254.0
ip helper-address 172.16.10.13 dhcp
ip helper-address 172.16.10.14 dhcp
exit
interface vlan 22
ip address 172.16.22.1 255.255.254.0
ip helper-address 172.16.10.13 dhcp
ip helper-address 172.16.10.14 dhcp
exit
interface vlan 26
ip address 172.16.26.1 255.255.254.0
ip helper-address 172.16.10.13 dhcp
ip helper-address 172.16.10.14 dhcp
exit
interface vlan 30
ip address 172.16.30.1 255.255.254.0
ip helper-address 172.16.10.13 dhcp
ip helper-address 172.16.10.14 dhcp
exit
interface vlan 34
ip address 172.16.34.1 255.255.254.0
ip helper-address 172.16.10.13 dhcp
ip helper-address 172.16.10.14 dhcp
exit
interface vlan 1051
ip address 10.0.51.1 255.255.255.252
exit
ip route 0.0.0.0 0.0.0.0 172.16.10.3
ip route 172.16.120.0 255.255.254.0 10.0.51.2

 

Datacenter N4064F

Default Gateway is 172.16.120.3
S *0.0.0.0/0 [1/0] via 172.16.120.3, 219d:07h:44m, Vl120
C *10.0.51.0/30 [0/0] directly connected, Vl1051
S *172.16.10.0/23 [1/0] via 10.0.51.1, Vl1051
S *172.16.14.0/23 [1/0] via 10.0.51.1, Vl1051
S *172.16.18.0/23 [1/0] via 10.0.51.1, Vl1051
S *172.16.22.0/23 [1/0] via 10.0.51.1, Vl1051
S *172.16.26.0/23 [1/0] via 10.0.51.1, Vl1051
C *172.16.120.0/23 [0/0] directly connected, Vl120

system jumbo mtu 9216
ip http timeout-policy idle 300 life 86400
no ip redirects
ip routing
interface vlan 1
exit
interface vlan 120
ip address 172.16.120.1 255.255.254.0
bandwidth 10000
exit
interface vlan 1051
ip address 10.0.51.2 255.255.255.252
exit
ip route 0.0.0.0 0.0.0.0 172.16.120.3
ip route 172.16.10.0 255.255.254.0 10.0.51.1
ip route 172.16.14.0 255.255.254.0 10.0.51.1
ip route 172.16.18.0 255.255.254.0 10.0.51.1
ip route 172.16.22.0 255.255.254.0 10.0.51.1
ip route 172.16.26.0 255.255.254.0 10.0.51.1