Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Inter vlan Routing does not work

Dear boss

I have cisco 3845 router  and 4507 & 2960 switch.  I have 4 Vlans on 4507  and connected to router on  four ports. Its working fine.

Now i want to create another vlan ( vlan 15 ) that trunk with vlan 20 and router port f0/0/1. i.e router F 0/0/1 ports belongs only two vlan(15,20) and need to intervlan routing. My conf. given below. but it is not working.

Switch conf:

interface GigabitEthernet3/1

description ## to router##

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 15-21

switchport mode trunk

interface Vlan15

ip address 192.168.3.250 255.255.255.0

!

interface Vlan20

ip address 192.168.0.250 255.255.255.0

interface GigabitEthernet3/2

description ## To local lan-15 ##

switchport acc vlan 15

interface GigabitEthernet3/3

description  ## To Local lan-20 ##

switch port acc vlan 20

ip route 0.0.0.0 0.0.0.0 192.168.0.252

Router conf:

interface FastEthernet0/0/1

ip address 192.168.0.252 255.255.255.0

ip flow ingress

ip flow egress

ip nat outside

ip virtual-reassembly

duplex auto

speed auto

ntp broadcast

standby 4 ip 192.168.0.254

standby 4 priority 140

standby 4 preempt

standby 4 track GigabitEthernet0/1

standby 4 track FastEthernet0/0/0

standby 4 track GigabitEthernet0/0

!

interface FastEthernet0/0/1.2

encapsulation dot1Q 15

ip address 192.168.3.252 255.255.255.0

How can i do intervlan routing as ping from vlan 15 to 20.

shahid

2 ACCEPTED SOLUTIONS

Accepted Solutions
Hall of Fame Super Gold

Re: Inter vlan Routing does not work

Configure some router subinterface for encapsulation dot1Q 20

Anyway since you have a layer3 switch, it is better to configure inter-vlan routing there and not on the router.

VIP Purple

Re: Inter vlan Routing does not work

HI Shahid,

I am agree with Paolo.

you have to configure subinterfaces for encapsulation.

see the example:If you are configuring on Router


Create sub-interfaces, set 802.1Q trunking protocol and ip address on each sub-interface

Router(config)#interface f0/0
Router(config-if)#no shutdown

(Note: The main interface f0/0 doesn’t need an IP address but it must be turned on)

Router(config)#interface f0/0.0
Router(config-subif)#encapsulation dot1q 15
Router(config-subif)#ip address 192.168.15.1 255.255.255.0
Router(config-subif)#interface f0/0.1
Router(config-subif)#encapsulation dot11 20
Router(config-subif)#ip address 192.168.20.1 255.255.255.0

(Note: In the “encapsulation dot1q 15″ command, 15 is the VLAN ID this interface operates in)

Configure VLAN

Switch(config)#vlan 15
Switch(config-vlan)#name SALES
Switch(config-vlan)#vlan 20
Switch(config-vlan)#name TECH

Set ports to access mode & assign ports to VLAN

Switch(config)#interface range fa0/1
Switch(config-if)#no shutdown
Switch(config-if)# switchport mode access
Switch(config-if)# switchport access vlan 15
Switch(config-if)#interface range fa0/3
Switch(config-if)#no shutdown
Switch(config-if)#switchport mode access
Switch(config-if)# switchport access vlan 20

see the example:If you are configuring on layer 3 switch:

ip routing
!
interface FastEthernet0/1
switchport access vlan 10
switchport mode access
!
interface FastEthernet0/3
switchport access vlan 20
switchport mode access

interface Vlan15
ip address 192.168.15.1 255.255.255.0
!
interface Vlan20
ip address 192.168.20.1 255.255.255.0

And on hosts just assign IP addresses and default gateways (to the corresponding interface VLANs) -> hosts in different VLANs can communicate.

Regards

Please rate if it helps

4 REPLIES
Hall of Fame Super Gold

Re: Inter vlan Routing does not work

Configure some router subinterface for encapsulation dot1Q 20

Anyway since you have a layer3 switch, it is better to configure inter-vlan routing there and not on the router.

VIP Purple

Re: Inter vlan Routing does not work

HI Shahid,

I am agree with Paolo.

you have to configure subinterfaces for encapsulation.

see the example:If you are configuring on Router


Create sub-interfaces, set 802.1Q trunking protocol and ip address on each sub-interface

Router(config)#interface f0/0
Router(config-if)#no shutdown

(Note: The main interface f0/0 doesn’t need an IP address but it must be turned on)

Router(config)#interface f0/0.0
Router(config-subif)#encapsulation dot1q 15
Router(config-subif)#ip address 192.168.15.1 255.255.255.0
Router(config-subif)#interface f0/0.1
Router(config-subif)#encapsulation dot11 20
Router(config-subif)#ip address 192.168.20.1 255.255.255.0

(Note: In the “encapsulation dot1q 15″ command, 15 is the VLAN ID this interface operates in)

Configure VLAN

Switch(config)#vlan 15
Switch(config-vlan)#name SALES
Switch(config-vlan)#vlan 20
Switch(config-vlan)#name TECH

Set ports to access mode & assign ports to VLAN

Switch(config)#interface range fa0/1
Switch(config-if)#no shutdown
Switch(config-if)# switchport mode access
Switch(config-if)# switchport access vlan 15
Switch(config-if)#interface range fa0/3
Switch(config-if)#no shutdown
Switch(config-if)#switchport mode access
Switch(config-if)# switchport access vlan 20

see the example:If you are configuring on layer 3 switch:

ip routing
!
interface FastEthernet0/1
switchport access vlan 10
switchport mode access
!
interface FastEthernet0/3
switchport access vlan 20
switchport mode access

interface Vlan15
ip address 192.168.15.1 255.255.255.0
!
interface Vlan20
ip address 192.168.20.1 255.255.255.0

And on hosts just assign IP addresses and default gateways (to the corresponding interface VLANs) -> hosts in different VLANs can communicate.

Regards

Please rate if it helps

New Member

Inter vlan Routing does not work

Mr. Sandeep

Thank you very much for such clear concept with example.

shahid

Gold

Re: Inter vlan Routing does not work

Hi Shahid,

Agree with Paolo, from ur post i have this impression that u r mostly using Gigabit switched interfaces, doing intervlan routing on a "Router on a stick" fashion with Fastethernet interfaces could seriously slow down ur network. use the Layer 3 Capability.

Hope it Helps,

Soroush.

Hope it Helps, Soroush.
1073
Views
0
Helpful
4
Replies