Comware Based
cancel
Showing results for 
Search instead for 
Did you mean: 

BFD for OSPF useful on multi-vlans link ??

Arthis
Occasional Advisor

BFD for OSPF useful on multi-vlans link ??

 

 

On a ring using RRPP, we have several protected vlans (vlan 2 to 20, including a vlan 13). The VLAN 13 is an OSPF routing vlan.

 

Just to give you an idea, here's the topology and the configuration applied to HP10500VIL

 

 

 

RRPP & Layer3.jpg

 

 

I've decided to configure BFD for OSPF on interface vlan 13.

 

But, now I'm wondering  if BFD is an appropriate mechanism on a link with several vlans.

 

OIndeed, one day, we had a BFD failure (see the logs below). No updown link, no RRPP failure.

 

To my mind, the BFD packet was not received before 300ms and an OSPF  reconvergence occurs.

 

Should I disable BFD on my vlan 13 ??  If you have any idea ...?

 

Thanks

 

Herve

 

-------------------------------------------------------------------

HP10500VIL:

 

%Jun 10 09:35:32:631 2013 HP10500VIL BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.8/10.61.5.9,516/33,Vlan13,Ctrl], Sta: UP->DOWN, Diag: 5

%Jun 10 09:35:32:632 2013 HP10500VIL OSPF/6/OSPF_LAST_NBR_DOWN: OSPF 1 Last neighbor down event: Router ID: 10.61.5.9 Local address: 10.61.5.8 Remote

address: 10.61.5.9 Reason: BFD session down.

%Jun 10 09:35:32:782 2013 HP10500VIL OSPF/5/OSPF_NBR_CHG: OSPF 1 Neighbor

10.61.5.9(Vlan-interface13) from Full to Down.

%Jun 10 09:35:41:494 2013 HP10500VIL OSPF/5/OSPF_NBR_CHG: OSPF 1 Neighbor

10.61.5.9(Vlan-interface13) from Loading to Full.

%Jun 10 09:35:41:655 2013 HP10500VIL BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.8/10.61.5.9,517/36,Vlan13,Ctrl], Sta: DOWN->INIT, Diag: 0 %Jun 10 09:35:41:815 2013 HP10500VIL BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.8/10.61.5.9,517/36,Vlan13,Ctrl], Sta: INIT->UP, Diag: 0 

 

 

HP10500CAL:

 

%Jun 10 09:35:32:727 2013 HP10500CAL BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.7/10.61.5.9,516/34,Vlan13,Ctrl], Sta: UP->DOWN, Diag: 5

%Jun 10 09:35:32:734 2013 HP10500CAL OSPF/6/OSPF_LAST_NBR_DOWN: OSPF 1 Last neighbor down event: Router ID: 10.61.5.9 Local address: 10.61.5.7 Remote

address: 10.61.5.9 Reason: BFD session down.

%Jun 10 09:35:32:734 2013 HP10500CAL OSPF/5/OSPF_NBR_CHG: OSPF 1 Neighbor

10.61.5.9(Vlan-interface13) from Full to Down.

%Jun 10 09:35:40:617 2013 HP10500CAL OSPF/5/OSPF_NBR_CHG: OSPF 1 Neighbor

10.61.5.9(Vlan-interface13) from Loading to Full.

%Jun 10 09:35:40:905 2013 HP10500CAL BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.7/10.61.5.9,517/35,Vlan13,Ctrl], Sta: DOWN->INIT, Diag: 0 %Jun 10 09:35:40:926 2013 HP10500CAL BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.7/10.61.5.9,517/35,Vlan13,Ctrl], Sta: INIT->UP, Diag: 0 

 

HP500LYO:

 

%Jun 10 09:35:32:456 2013 HP5500LYO BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.9/10.61.5.8,33/516,Vlan13,Ctrl], Sta: UP->DOWN, Diag: 5 %Jun 10 09:35:32:463 2013 HP5500LYO OSPF/6/OSPF_LAST_NBR_DOWN: OSPF 1 Last neighbor down event: Router ID: 10.61.5.8 Local address: 10.61.5.9 Remote

address: 10.61.5.8 Reason: BFD session down.

%Jun 10 09:35:32:464 2013 HP5500LYO OSPF/5/OSPF_NBR_CHG: OSPF 1 Neighbor

10.61.5.8(Vlan-interface13) from Full to Down.

%Jun 10 09:35:32:722 2013 HP5500LYO BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.9/10.61.5.7,34/516,Vlan13,Ctrl], Sta: UP->DOWN, Diag: 5 %Jun 10 09:35:32:732 2013 HP5500LYO OSPF/6/OSPF_LAST_NBR_DOWN: OSPF 1 Last neighbor down event: Router ID: 10.61.5.7 Local address: 10.61.5.9 Remote

address: 10.61.5.7 Reason: BFD session down.

%Jun 10 09:35:32:732 2013 HP5500LYO OSPF/5/OSPF_NBR_CHG: OSPF 1 Neighbor

10.61.5.7(Vlan-interface13) from Full to Down.

%Jun 10 09:35:37:459 2013 HP5500LYO RM/3/RMLOG: The default route has been changed or deleted, protocol is OSPF, nexthop address is 10.61.5.8, output interface is Vlan-interface13

%Jun 10 09:35:37:459 2013 HP5500LYO RM/3/RMLOG: The default route has been changed or deleted, protocol is OSPF, nexthop address is 10.61.5.7, output interface is Vlan-interface13

%Jun 10 09:35:40:616 2013 HP5500LYO OSPF/5/OSPF_NBR_CHG: OSPF 1 Neighbor

10.61.5.7(Vlan-interface13) from Loading to Full.

%Jun 10 09:35:40:815 2013 HP5500LYO OSPF/5/OSPF_NBR_CHG: OSPF 1 Neighbor

10.61.5.8(Vlan-interface13) from Loading to Full.

%Jun 10 09:35:40:922 2013 HP5500LYO BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.9/10.61.5.7,35/517,Vlan13,Ctrl], Sta: DOWN->UP, Diag: 0 %Jun 10 09:35:40:923 2013 HP5500LYO BFD/5/BFD_CHANGE_FSM: Sess [10.61.5.9/10.61.5.8,36/517,Vlan13,Ctrl], Sta: DOWN->UP, Diag: 0 %

1 REPLY
manuel.bitzi
Trusted Contributor

Re: BFD for OSPF useful on multi-vlans link ??

Hi Arthis

 

OSPF BFD only make sence when you have a Layer3 backup path if the connection breaks. That will speed up the convergency.

 

As I see in your topology there is no L3 backup path (RRPP is L2), beacuse that OSPF BFD doesn't bring any improvments to the network. Disable it to avoid problems with a protocol which is not nessesary.

 

 

Best regards

Manuel

H3CSE, MASE Network Infrastructure [2011], Switzerland