Migration of Cisco BVI configuration to BDI

[Abdulla Ydyrys]

Hello Dears,
In our environment, we have a Cisco 2911 Router (IOS). We are now planning to replace it with a Cisco C8200L Router (IOS-XE). In the old router, we have BVI implemented. Since this feature is called BDI in IOS-XE, I have migrated the configuration accordingly.

Cisco 2911 Router (IOS) configuration:
bridge irb
bridge 1 priority 0
bridge 1 protocol ieee
bridge 1 route ip

interface GigabitEthernet0/1
no ip address
duplex auto
speed auto
no cdp enable
bridge-group 1
!
interface GigabitEthernet0/2
no ip address
duplex auto
speed auto
no cdp enable
bridge-group 1
!
interface BVI1
ip address 192.168.50.1 255.255.255.0
!

Cisco C8200L Router (IOS-XE) configuration:

int g0/0/1
service instance 5 ethernet
encapsulation untagged
bridge-domain 5

int g0/0/2
service instance 5 ethernet
encapsulation untagged
bridge-domain 5

int BDI5
ip address 192.168.50.1 255.255.255.0
!

Router interfaces Gi0/0/1 and Gi0/0/2 are connected to two physical switches in a stack (appearing as one logical switch) through ports Gi1/0/1 and Gi2/0/1, and these ports are configured in access mode. 

Switch configuration:

int gi1/0/1
switchport mode access
switchport access vlan 800
spanning-tree portfast

int gi2/0/1
switchport mode access
switchport access vlan 800
spanning-tree portfast

Previously, in the old router, everything worked correctly, but when I plugged in cables to the new router, connectivity was lost. In the logs, I see these errors:

Aug 24 2023 17:52:14.516 ALM: %IOSXE-5-PLATFORM: R0/0: cpp_cp: QFP:0.0 Thread:000 TS:00000000297525326090 %PUNT_INJECT-5-DROP_PUNT_CAUSE: punt policer drops packets, cause: for-us-ctrl (0x37) from BDI5 src ip: 192.168.50.2

IOSXE_QFP-2-LOAD_EXCEED: Slot: 0, QFP:0, Load 85% exceeds the setting threshold 80%

The IOS-XE version is 17.6.1a. If I shut down one interface, for example, Gi0/0/2, the traffic flows, and the connection is restored. So, what could be the issue with the configuration? Do you have any suggestions?

[Joseph W. Doherty]

The traffic flows when you shut an interface???

That aside, I'm wondering whether the 8200L has data plane hardware, and because of uses a lower capacity CPU.  If so, if BDI traffic must be done on CPU, your volume of traffic is being limited.

If the forgoing is true, the only solution might be, don't use the 8200L in this manner.  (A 4 gig port dumb L2 switch might be an inexpensive work around solution.)

Hopefully, someone else will provide a better issue explanation and solution.

[Abdulla Ydyrys]

Two interfaces combined into one Bridge domain interface. When only one interface is up, traffic flows; when both interfaces are up, the connection is lost. 

[paul driver]

Hello
Try rewrite/drop the tag as it comes into the BDI for the switch stack

Int xx
rewrite ingress tag pop 1 symmetric

[Giuseppe Larosa]

Hello @Abdulla Ydyrys ,

the messages below:

>>

Aug 24 2023 17:52:14.516 ALM: %IOSXE-5-PLATFORM: R0/0: cpp_cp: QFP:0.0 Thread:000 TS:00000000297525326090 %PUNT_INJECT-5-DROP_PUNT_CAUSE: punt policer drops packets, cause: for-us-ctrl (0x37) from BDI5 src ip: 192.168.50.2

IOSXE_QFP-2-LOAD_EXCEED: Slot: 0, QFP:0, Load 85% exceeds the setting threshold 80%

Make me think that with two interfaces connected a bridging loop is formed.

When you shut one interface the bridging loop is removed and connectivity works again.

Hope to help

Giuseppe