Cisco 1941 with 2 internet connections malfunctioning

[Tommy Svensson]

Hi.

Im trying to set up a Cisco 1941 router with two Internet connections, one 24Mbit that will be the main connection where the traffic is suppose to be going and one 4Mbit for backup.

I have a Cisco 1941 with an additional switchmodule with 4 port layer two functionality.

The scenario is that i want VLAN 1 to be assigned so that the switchport vill be the way out to the LAN network. For that i need a subinterface for the VLAN. And when i try to add subinterface    
interface giga0/0.1

     encapsulation dot1q 1

the routing does not work anymore. My default gateway for the router is 192.168.96.1. Something is happening when i add the subinterface to the router.

Regards Tommy Svensson

interface GigabitEthernet0/0
description LINK_TO_ADSL
bandwidth 24576
backup interface GigabitEthernet0/1
ip address 192.168.96.20 255.255.255.0
ip nbar protocol-discovery
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet0/1
description LINK_TO_VPN
ip address 10.0.2.1 255.255.255.0
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
!
interface FastEthernet0/0/0
description LAYER_2
!
interface FastEthernet0/0/1
description LAYER_2
!
interface FastEthernet0/0/2
description LAYER_2
!
interface FastEthernet0/0/3
description LAYER_2
!
interface Vlan1
no ip address
!
ip forward-protocol nd
!
!
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0
!
access-list 10 permit 10.0.0.0 0.0.0.255
access-list 10 permit 10.0.1.0 0.0.0.255
!
!
line con 0
logging synchronous
login local
line aux 0
line vty 0 4
privilege level 15
logging synchronous
login local
transport input ssh
line vty 5 15
privilege level 15
logging synchronous
login local
transport input ssh
!
scheduler allocate 20000 1000
end

[Jon Marshall · Accepted solution]

Tommy

It's not entirely clear what you are trying to do.

If gi0/0 is the internet connection then you don't add a subinterface there for vlan 1.

What you do is -

1) under the vlan 1 interface in your config allocate the IP address you were going to add to the subinterface -

int vlan 1

ip address x.x.x.x

2) then on the port that connects to your LAN switch eg. -

int fa0/0/0

switchport mode access

switchport access vlan 1

edit - if the clients on your LAN switch are in vlan 1 then use the IP address assigned to the vlan 1 interface on the router as their default-gateway. If you have a L3 switch in your  LAN used for inter-vlan routing then let me know how that is setup.

Jon