Cisco Catalyst 2960G - Limited routing
You can use SDM templates to configure system resources in the Catalyst 2960 switch to optimize support for specific features, depending on how the switch is used in the network. You can select a template to provide maximum system usage for some functions or use the default template to balance resources.
Default: The default template gives balance to all functions.
Dual: The dual IPv4 and IPv6 template allows the switch to be used in dual stack environments (supporting both IPv4 and IPv6). Using the dual stack templates results in less TCAM capacity allowed for each resource. Do not use them if you plan to forward only IPv4 traffic.
base routing: The lanbase-routing template supports IPv4 unicast routes for configuring static routing SVIs.
QoS: The QoS template maximizes system resources for quality of service (QoS) access control entries (ACEs).
When you select and configure SDM templates, you must reload the switch for the configuration to take effect.
Do not use the routing template if you do not have routing enabled on your switch. The sdm prefer lanbase routing global configuration command prevents other features from using the memory allocated to unicast routing in the routing template.
If you try to configure IPv6 features without first selecting a dual IPv4 and IPv6 template, a warning message appears.
Setting the SDM Template
Enter global configuration mode.
Specify the SDM template to be used on the switch:
sdm prefer lanbase-routing
Return to privileged EXEC mode.
Reload the operating system.
Verify template setting.
show sdm prefer
It seems the default gateway ip default-gateway setting does not work for NTP.
Add default gateway route
#ip route 0.0.0.0 0.0.0.0 18.104.22.168