Symptom
MVPN Profiles : Data MDT traffic not flowing with 2 paths when OSPF/ISIS cost/metric configured on 1 path
Conditions
Topology
Traffic Src--> MCAST SOURCE ------P1--------- CORE1 ------------ MCAST Receiver
| |
| |
|------------P2 -------------CORE2-----------------------|
P1 - Link 1 to reach MCAST receiver
P2 - Link 2 to reach MCAST receiver
MCAST Source - PE1
MCAST Receiver- PE2
CORE1 - P1
CORE2 - P2
Steps to Repro:
1. Configure MVPN profile 14 on PE1 , PE2 , P1 and P2.
2. Configure OSPF Cost on Path towards PE1 --- P2 , MPLS IP and BGP for VRF
3. Make sure OSPF , LDP , MLDP , BGP adjacencies are formed.
4. Send traffic from Traffic source to Traffic receiver
5. Traffic is not flowing from Source to receiver
6. Shutdown the path from PE1 --- P2 -----> Traffic starts to flow from Traffic src to receiver
7. Make the path up again from PE1 --- P2 -----> Traffic stops to flow from Traffic src to receiver
8. Remove the OSPF cost from PE1 --- P2 -----> Traffic starts to flow from Traffic src to receiver
9. Configure the OSPF cost from PE1 --- P2 -----> Traffic stops to flow from Traffic src to receiver
Seeing failures in steps 7 and 9 which is not expected.
Workaround
Remove OSPF/ISIS cost/metric from PE1 towards P2
Further Problem Description
Seeing failures in steps 7 and 9 which is not expected.
Note : This issue will be seen with ISIS / OSPF and will be applicable to all MVPN profiles since the issue is due to MLDP not able to establish route on interface where Cost / Metric is configured.
