cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
2559
Views
0
Helpful
3
Replies

Problems with VLANs between cisco 7200 routers

jlamanna1
Level 1
Level 1

Hi,

I have a point to point link between 2 Cisco 7200s that I'm being

required to add VLAN tagging to.

Here are the interface configs:

Router A:

interface FastEthernet5/0

no ip address

duplex full

!

interface FastEthernet5/0.253

encapsulation dot1Q 253

ip address xxx.xxx.xxx.249 255.255.255.252

Router B:

interface FastEthernet4/0

no ip address

duplex full

!

interface FastEthernet4/0.253

encapsulation dot1Q 253

ip address xxx.xxx.xxx.250 255.255.255.252

However, when AT&T forces tagging on the ports, I cannot ping from .

249 to .250, and AT&T cannot see my MAC address on their switches

inbetween and zero traffic on the VLAN.

Does anyone have any ideas?

Router A is a 7206VXR running 12.2(4r)

Router B is a 7204VXR running 12.2(12a)

Thank you.

3 Replies 3

Jon Marshall
Hall of Fame
Hall of Fame

Can you check with your provider

1) That they have configured the link as 802.1q trunk

2) That vlan 253 exists on their switch infrastructure

Jon

Yes.

I know they have configured the link as 802.1q on vlan 253.

I had a similar issue on a couple of our routers they are 2811s, but probably a similar situation. I had to to VLAN tagging for a different reason, but had similar results. What I wound up doing was to remove the IP address from the subinterface and put on apply to the parent interface. Here is a snippet from the config.

!

interface FastEthernet0/1

ip address xx.xx.245.65 255.255.255.252

duplex auto

speed auto

!

interface FastEthernet0/1.1

description $ETH-LAN$

encapsulation dot1Q 20

no snmp trap link-status

!

Once I did that it worked fine.

The HQ end was different because of the hardware we used.

Review Cisco Networking products for a $25 gift card