We have a 2811 router (IOS v 12.4(25)) which currently port F0/0 is connected to a 6509-E switch (6509-E1, IOS v 12.2(18)) via port f4/43 configured as a switch port in VLAN 502. Port f0/1 on the 2811 has a public IP address for PAT. Our public wireless goes thru a 4402 WLC which is on another 6509-E switch (6509-E2, IOS v 12.2(18)). The current IP network on VLAN 502 is 10.50.2. The setup of this network is working fine now but we do need to expand by adding more VLANs for other guest wireless networks.

My goal is to create sub interfaces on port F0/0 on the 2811 for different VLANs for our different guest wireless networks and change VLAN 502 IP addressing to 172.31. When I implement the configuration below in production, from the 4402 WLC I cannot ping IP address 172.31.255.254 which is subinterface f0/0.502 on the 2811. I setup the same configuration in GNS3 which worked without a problem, minus the 4402 which I substituted a router.

Appreciate any help.

Jeff

2811 Router:
ip dhcp pool 502
network 172.31.0.0 255.255.0.0
dns-server 66.155.216.122 8.8.8.8
default-router 172.31.255.254
lease 0 1

ip dhcp pool 600
network 10.60.0.0 255.255.255.0
dns-server 66.155.216.122 8.8.8.8
default-router 10.60.0.254
lease 14

access-list 1 permit 172.31.0.0 0.0.255.255
access-list 1 permit 10.60.0.0 0.0.0.255

ip nat inside source list 1 interface FastEthernet0/1 overload

int f0/0
no ip address 10.50.2.254 255.255.252.0
no ip nat inside
no ip virtual-reassembly

int f0/0.502
ip nat inside
encapsulation dot1q 502
ip address 172.31.255.254 255.255.0.0
no shut

int f0/0.600
ip nat inside
encapsulation dot1q 600
ip address 10.60.0.254 255.255.255.0
no shut

6509E-1:
int f4/43
switchport
switchport mode trunk
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 502
switchport trunk allowed vlan add 600

6509E-2:
int g3/2
switchport
switchport mode trunk
switchport trunk encapsulation dot1q

4402 WLC:
Interface Public_Wireless
VLAN 502
IP Address: 172.31.255.250

Hi Jeff,

I will appreciate if you can snapshot the network in GNS3 and post it to us here, that will help allot understanding the scenario.

Regards

Leopardy

Problem resolved,

The order of trunk commands appears to be very important with a 6509E running IOS as based on a suggestion from another post the correct order which worked is the following. Thanks.

interface FastEthernet4/43

switchport trunk encapsulation dot1q

switchport mode trunk

switchport trunk allowed vlan 502

spanning-tree portfast trunk