This is driving me nuts. There are 2 vlans on the switch( vlan 20 and 21.) one trunking port g0/1 and thats connected to a Router On A Stick. I CANT PING DIVINCES ON SEPARATE VLANS NOR THE ROUTER FROM THE PCs. HELP!!!!!
Interface configuration on the switch:
interface FastEthernet0/1 switchport access vlan 21 switchport mode access switchport nonegotiate spanning-tree portfast ! interface FastEthernet0/2 switchport access vlan 21 switchport mode access switchport nonegotiate spanning-tree portfast ! interface FastEthernet0/3 switchport access vlan 20 switchport mode access switchport nonegotiate spanning-tree portfast ! interface FastEthernet0/4 switchport access vlan 20 switchport mode access switchport nonegotiate spanning-tree portfast ! interface FastEthernet0/5 ! interface FastEthernet0/6 ! interface FastEthernet0/7 ! interface FastEthernet0/8 ! interface FastEthernet0/9 ! interface FastEthernet0/10 ! interface FastEthernet0/11 ! interface FastEthernet0/12 ! interface FastEthernet0/13 ! interface FastEthernet0/14 ! interface FastEthernet0/15 ! interface FastEthernet0/16 ! interface FastEthernet0/17 ! interface FastEthernet0/18 ! interface FastEthernet0/19 ! interface FastEthernet0/20 ! interface FastEthernet0/21 ! interface FastEthernet0/22 ! interface FastEthernet0/23 ! interface FastEthernet0/24 ! interface GigabitEthernet0/1 switchport trunk allowed vlan 20-21 switchport trunk encapsulation dot1q ! interface GigabitEthernet0/2 !
Note the interface connecting switch to router( the one on the switch is gig 0/1)
configuration on router interface g0/0 as its the one connecting to the switch below
interface GigabitEthernet0/0 no ip address duplex auto speed auto ! interface GigabitEthernet0/0.20 encapsulation dot1Q 20 ip address 150.19.20.6 255.255.255.248 ! interface GigabitEthernet0/0.21 encapsulation dot1Q 21 ip address 150.19.21.6 255.255.255.248 !