Hi Experts,
I am facing a routing loop issue in my network and wanted to understand how I can control the routes learnt in DC1 - WAN ( L3 outs) not to be advertising from DC2.
Current scenario.
Old DC - 6800 Core switch - Server gateway & Old DC and New DC1 are connected via dark fiber L2 link.
Old DC connected to ISP using OSPF and BGP running at the ISP end.
DC1 -we are using ACI
PRDN - VRF1 - L3out- Leaf 1 interface profile- Primary link - Point to Point OSPF - ISP R1
PRDN - VRF1- L3Out - Leaf2 interface profile - Secondary link- P2P OSPF - ISP R2.
DC2 - We are using ACI connected to DC1 via multi-pod and communication is UP
DC2 is considered also as DR site.
PRDN - VRF1 - L3out- Leaf 1 interface profile- Primary link - Point to Point OSPF - ISP R1
PRDN - VRF1- L3Out - Leaf2 interface profile - Secondary link- P2P OSPF - ISP R2.
Requirement:
We want to move one Vlan from old DC to DC1 and make BD as a gateway - ( Vlan -10- 10.1.1.0/24)
Host in this vlan already communicate between old dc1 to DC1
Step1: Shutdown vlan on Old DC core switch
Step2: Assign the subnet inside BD1 and call the L3 Out1
Step3: Created a new vlan in old DC towards DC1; created a new VRF#2
SVI for L3 traffic over L2 link
Old DC
192.168.1.1/30
DC1
VRF#2 ; BD2 - 192.168.1.2/30
Allow this vlan over L2 link
Step4: New L3out : Leaf 1 & 2 -
Static route: Target route : 10.2.0.0/22 net hop : 192.168.1.1
Ext.EPG - 0.0.0.0 - Export route control subnet
10.2.0.0/22 - Export route control subnet.
After this ping from old DC to DC1 through L2 link is established
DC1 - ping success to 192.168.1.1
Step5: Perform route leaking in VRF1 for ( BD Vlan10 - 10.1.1.0/24) towards VRF2 in the same tenant.
Issue statement: after step4: old DC subnet 10.2.0.0/22 were started advertising from DC2 for all the branches and thus created the Routing Loop. I guess VRF2 has become a transit and then 10.2.0.0/22 routes were sent to DC2 via IPN link.
Now, I want to know how can I control this by performing prefix-list in DC1 and DC2, so that each site should advertise its own routes.
Note: DC1 and DC2 are using Ospf towards ISP routers and ISP using BGP and they get redistributed.
Appreciate your quick response.
