[c-nsp] BFD on PortChannel interface (IOS-XE)

[Pshem Kowalczyk]

Hi,

I'm trying to figure out if BFD is supported on a PortChannel
interface on IOS-XE (3.1.0S) on ASR1006. Configuration is accepted but
then the session never comes up:


#sh bfd neighbors details

NeighAddr                         LD/RD    RH/RS     State     Int
10.123.223.1                       2/0     Down      Down      Po1.600
OurAddr: 10.123.223.2
Local Diag: 0, Demand mode: 0, Poll bit: 0
MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 3
Received MinRxInt: 0, Received Multiplier: 0
Holddown (hits): 0(0), Hello (hits): 1000(1139)
Rx Count: 0, Rx Interval (ms) min/max/avg: 0/0/0 last: 1137045694 ms ago
Tx Count: 1139, Tx Interval (ms) min/max/avg: 754/1000/875 last: 816 ms ago
Elapsed time watermarks: 0 0 (last: 0)
Registered protocols: CEF ISIS
Last packet: Version: 1                  - Diagnostic: 0
             State bit: AdminDown        - Demand bit: 0
             Poll bit: 0                 - Final bit: 0
             Multiplier: 0               - Length: 0
             My Discr.: 0                - Your Discr.: 0
             Min tx interval: 0          - Min rx interval: 0
             Min Echo interval: 0


>From this output it looks like the box is not receiving any BFD
packets, but if I disconnect the PortChannel and do it on a native
interface - it comes up fine:



NeighAddr                         LD/RD    RH/RS     State     Int
10.123.223.65                      1/589844 Up        Up        Gi0/0/0
Session state is UP and using echo function with 999 ms interval.
OurAddr: 10.123.223.66
Local Diag: 0, Demand mode: 0, Poll bit: 0
MinTxInt: 1000000, MinRxInt: 1000000, Multiplier: 3
Received MinRxInt: 2000000, Received Multiplier: 3
Holddown (hits): 0(0), Hello (hits): 2000(7006)
Rx Count: 6719, Rx Interval (ms) min/max/avg: 1/2008/1830 last: 1537 ms ago
Tx Count: 7008, Tx Interval (ms) min/max/avg: 1/2015/1756 last: 923 ms ago
Elapsed time watermarks: 0 0 (last: 0)
Registered protocols: CEF ISIS
Uptime: 00:14:55
Last packet: Version: 1                  - Diagnostic: 0
             State bit: Up               - Demand bit: 0
             Poll bit: 0                 - Final bit: 0
             Multiplier: 3               - Length: 24
             My Discr.: 589844           - Your Discr.: 1
             Min tx interval: 2000000    - Min rx interval: 2000000
             Min Echo interval: 1000

(different interface on the same device)

The configuration is exactly the same in both cases:


 bfd interval 999 min_rx 999 multiplier 3
 isis bfd

on the Portchannel I can only set timers to 999ms as minimum, on the
physical interface it allows to go down to 50ms.

It there something else that should be configured, or is it simply not
supported? I looked through the bugs, but can't find anything that
looks relevant.

kind regards
Pshem