in the switch:
3524xl(config)#int fastEthernet 0/48
3524xl(config-if)#switchport trunk encapsulation dot1q
3524xl(config-if)#switchport mode trunk
3524xl(config-if)#switchport trunk allowed vlan all
3524xl(config-if)#exit
3524XL#vlan database
3524XL(vlan)#vlan 2 name cisco_vlan_2
3524XL(vlan)#exit
APPLY completed.
3524XL#configure terminal
3524XL(config)#interface fastEthernet 0/2
3524XL(config-if)#switchport access vlan 2
3524XL(config-if)#exit
3524XL(config)#interface fastEthernet 0/3
3524XL(config-if)#switchport access vlan 2
3524XL(config-if)#end
in the rtr:
interface FastEthernet0/0
no ip address
!
interface FastEthernet0/0.1
encapsulation dot1Q 1 native
ip address 10.10.10.1 255.255.255.0
!
interface FastEthernet0/0.2
encapsulation dot1Q 2
ip address 10.10.11.1 255.255.255.0
