Route from layer 3 switch to router to internet

user34534534 · ‎06-19-2014

Hey guys,

I'm trying to figure out how to route packets not in the subnet out the switch to the router and then to the cable modem.

I'm guessing I have to set a static route but I can't figure out how.

I'm lost when it comes to fa0/3 on the L3 switch and fa0/0 on the router. The config files are below. Can anyone help?

Thanks!

R1:

Current configuration : 547 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router
!
!
!
!
!
!
!
!
!
!
!
!
!
!
spanning-tree mode pvst
!
!
!
!
interface FastEthernet0/0
no ip address
duplex auto
speed auto
!
interface FastEthernet0/0.6
encapsulation dot1Q 6
no ip address
!
interface FastEthernet0/1
no ip address
duplex auto
speed auto
shutdown
!
interface Vlan1
no ip address
shutdown
!
ip classless
!
!
!
!
!
!
!
line con 0
!
line aux 0
!
line vty 0 4
login
!
!
!
end

S1:

Current configuration : 1495 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Switch
!
!
!
!
!
ip routing
!
!
!
!
!
!
!
!
!
!
spanning-tree mode pvst
!
!
!
!
interface FastEthernet0/1
switchport trunk allowed vlan 6-7
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/2
switchport trunk allowed vlan 6-7
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/3
switchport trunk allowed vlan 6-7
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/4
!
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
!
interface GigabitEthernet0/2
!
interface Vlan1
no ip address
shutdown
!
interface Vlan6
ip address 192.168.6.1 255.255.255.0
!
interface Vlan7
ip address 192.168.7.1 255.255.255.0
!
ip classless
!
!
!
!
!
!
!
line con 0
!
line aux 0
!
line vty 0 4
login
!
!
!
end

S2:

Current configuration : 1219 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Switch
!
!
!
!
spanning-tree mode pvst
!
interface FastEthernet0/1
switchport trunk allowed vlan 6-7
switchport mode trunk
!
interface FastEthernet0/2
switchport mode access
!
interface FastEthernet0/3
switchport access vlan 6
switchport mode access
!
interface FastEthernet0/4
switchport access vlan 7
switchport mode access
!
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 GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Vlan1
no ip address
shutdown
!
!
line con 0
!
line vty 0 4
login
line vty 5 15
login
!
!
end

S3:

Current configuration : 1121 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Switch
!
!
!
!
spanning-tree mode pvst
!
interface FastEthernet0/1
switchport trunk allowed vlan 6-7
switchport mode trunk
!
interface FastEthernet0/2
!
interface FastEthernet0/3
switchport access vlan 7
!
interface FastEthernet0/4
!
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 GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Vlan1
no ip address
shutdown
!
!
line con 0
!
line vty 0 4
login
line vty 5 15
login
!
!
end

mmoulson1 · ‎06-20-2014

If you trunk from the switch to the router then you would normally use the router as the default gateway so your performing your routing function on the router rather than the L3 switch. Config would on the router e.g.:

interface FastEthernet0/1
no ip address
!
interface FastEthernet0/1.6
description VLAN 6
encapsulation dot1Q 6
ip address 192.168.6.2 255.255.255.0
!
interface FastEthernet0/1.7
description VLAN 7
encapsulation dot1Q 7
ip address 192.168.7.2 255.255.255.0

Or setup a VLAN specifcially for routing out e.g. VLAN10. On the switch configure the switch port as an access port in VLAN10 and setup an SVI e.g. 192.168.10.1.

On the router configure Fa0/0 with an IP address 192.168.10.2.

Setup a default route on the switch to 192.168.10.2.

On the router setup static routes to 192.168.6.0/24 & 192.168.7.0/24 via 192.168.10.1

Hope that makes sense!

adamtodd16 · ‎06-23-2014

This is 100% correct.

If you're hosting your VLANs on the router and trunking to the switch, then the router has to do the routing.

If you want to do the routing on the switch, then the routing simply becomes a gateway and should be connected on an access port - preferably on a dedicated management VLAN.