07-24-2011 09:01 AM - edited 03-07-2019 01:22 AM
Hi guys,
I have had time to figure what is wrong on me setup. I receive an Internet feed via two gigabit interfaces. The provide offer me a dual home setup where the managed the routing (BGP4). Their way to provide an unique path is via VRRP. Me provide is using Extreme X450s switches at his end and on our side we are using Cisco Catalyst 4948.
Here is me port configuration:
sw1:
spanning-tree mode pvst
spanning-tree portfast default
spanning-tree portfast bpduguard default
spanning-tree extend system-id
no spanning-tree vlan 101
spanning-tree vlan 102,107 priority 16384
spanning-tree vlan 103 priority 8192
!
vlan internal allocation policy ascending
!
interface Port-channel22
description to-sw2
switchport trunk encapsulation dot1q
switchport trunk native vlan 155
switchport mode dynamic desirable
!
interface GigabitEthernet1/0/47
description to-sw2
switchport trunk encapsulation dot1q
switchport trunk native vlan 155
switchport mode dynamic desirable
channel-group 22 mode on
spanning-tree portfast disable
!
interface GigabitEthernet1/0/48
description to-sw2
switchport trunk encapsulation dot1q
switchport trunk native vlan 155
switchport mode dynamic desirable
channel-group 22 mode on
spanning-tree portfast disable
!
interface GigabitEthernet1/0/50
switchport access vlan 155
speed nonegotiate
no cdp enable
spanning-tree portfast disable
sw2:
spanning-tree mode pvst
spanning-tree portfast default
spanning-tree portfast bpduguard default
spanning-tree extend system-id
no spanning-tree vlan 101
spanning-tree vlan 102,107 priority 8192
spanning-tree vlan 103 priority 16384
!
vlan internal allocation policy ascending
!
interface Port-channel21
description to-sw1
switchport trunk encapsulation dot1q
switchport trunk native vlan 155
switchport mode dynamic desirable
!
interface GigabitEthernet1/0/47
description to-sw1
switchport trunk encapsulation dot1q
switchport trunk native vlan 155
switchport mode dynamic desirable
channel-group 21 mode on
spanning-tree portfast disable
!
interface GigabitEthernet1/0/48
description to-sw1
switchport trunk encapsulation dot1q
switchport trunk native vlan 155
switchport mode dynamic desirable
channel-group 21 mode on
spanning-tree portfast disable
!
interface GigabitEthernet1/0/50
description isp-link2
switchport access vlan 155
speed nonegotiate
no cdp enable
spanning-tree portfast disable
Me provider is saying that we don't send BPDU and that it is require for his setup to block a port. Do you have an idea how could I resolve this issue?
Here is the show spanning-tree detail for each interface:
SW1:
Port 50 (GigabitEthernet1/0/50) of VLAN0155 is forwarding
Port path cost 4, Port priority 128, Port Identifier 128.50.
Designated root has priority 4096, address 0004.9635.29b6
Designated bridge has priority 32923, address 0022.5602.5800
Designated port id is 128.50, designated path cost 20007
Timers: message age 0, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 31516, received 0
Port 656 (Port-channel22) of VLAN0155 is forwarding
Port path cost 3, Port priority 128, Port Identifier 128.656.
Designated root has priority 4096, address 0004.9635.29b6
Designated bridge has priority 32923, address 0022.be9e.7400
Designated port id is 128.648, designated path cost 20004
Timers: message age 3, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 3, received 31536
SW2:
Port 50 (GigabitEthernet1/0/50) of VLAN0155 is forwarding
Port path cost 4, Port priority 128, Port Identifier 128.50.
Designated root has priority 4096, address 0004.9635.29b6
Designated bridge has priority 8192, address 0004.9635.29e8
Designated port id is 128.47, designated path cost 20000
Timers: message age 2, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 3, received 31471
!
Port 648 (Port-channel21) of VLAN0155 is forwarding
Port path cost 3, Port priority 128, Port Identifier 128.648.
Designated root has priority 4096, address 0004.9635.29b6
Designated bridge has priority 32923, address 0022.be9e.7400
Designated port id is 128.648, designated path cost 20004
Timers: message age 0, forward delay 0, hold 0
Number of transitions to forwarding state: 1
Link type is point-to-point by default
BPDU: sent 31491, received 3
Jerome
07-24-2011 09:21 AM
Cant see the link between a layer 2 loop avoidance and dynamic layer 3 failover.
Why do you think a blocking spanning tree port will fix your issue?
Sent from Cisco Technical Support iPad App
07-24-2011 09:56 AM
Hello Jerome,
I agree with Andrew - the VRRP is probably not related to your issue with BPDUs.
I fail, however, to see the bigger picture. What are you actually trying to achieve? So far, we only understand that your ISP complains about some BPDUs missing from your side. However, what is to be achieved by that?
Furthemore, I am somewhat surprised by the information about the ports Gi1/0/50 on both switches. Specifically, on SW1, it says:
Timers: message age 0, forward delay 0, hold 0
I do not see any reason why should a port sending BPDUs have all STP timers set to 0.
Furthermore, on SW2, the same port says:
BPDU: sent 3, received 31471
The output says that this port is forwarding - does it mean that the Gi1/0/50 on SW2 is the root port? In that case, it would be logical that it does not send any BPDUs - root ports send BPDUs only during topology changes.
Best regards,
Peter
08-12-2011 08:05 AM
Hello Peter,
We found the problem. As I was suspecting our provider has misconfigured their setup and our layer 2 root bridge was onto another customer edge switch. The provider was trying to explain me that it was because we are having a BGP configuration, how lame is that response. They finally admit they screwed up their config and now the problem is resolved.
Thanks for your inputs,
Jerome
08-12-2011 08:11 AM
Hello Jerome,
You're welcome - although I have not helped much in your case. Thank you very much for being so kind to keep me informed about this issue. Hopefully, it will be working flawlessly from now on
Aaaah, the almighty, ever-truthful, flawless ISPs...
Best regards,
Peter
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