4. Why DCI is necessary?
• VM migrations
• IP renumbering
• VLAN Scaling
• Geo-cluster applications
• Disaster recovery
5. Challenges ?
• Broadcast storms: Unknown and broadcast frames may create excessive flood
• Loops: Easy to form loops in large networks
• Tromboning: Dual attached servers and switches generate excessive cross
traffic
• Security: Data on LAN extension must be encrypted
• STP Issues:
diameter: more than 7
Root can become bottleneck
Multiple path remain unused
7. OTV vs EVPN+VXLAN vs VPLS
• VXLAN gives us liberty to use 2^24 VLANS. VXLAN-EVPN is the data
centre technologies. In VPLS we have limited number of VLANS.
• In EVPN the mac-learning happens in control plane whereas in VPLS it
happens in data plane. Hence, In EVPN this feature reduces the
unknown unicast broadcast packets and wastage of resources.
• VXLAN is supported by virtual devices and as well as routers. VPLS Is
totally based on our backbone. No role in virtual devices.
8. OTV vs EVPN+VXLAN vs VPLS
• OTV does the L2 stretch at the core of the network as opposed to the
edge with EVPN.
• For core, more cost to deployment as there will be separate circuits
• Core is more expensive than Edge
9. OTV vs EVPN+VXLAN vs VPLS
• VPLS relies on MPLS transport; if your DCI link has to use IP
infrastructure, you have to configure MPLS over GRE tunnels before
you can configure VPLS.
• VPLS cannot do all-active forwarding
15. Consideration for best practices
• How STP avoid loops and broadcast storms?
• When we combine vMotion with stateful device
• Long distance vMotion led to trombing, only suggested in case of Disaster
avoidance
• How does provider router detect active IP address or subnet?
• Which scaling protocols, technology or products to use?
16. How SDN/Cloud era changing DCI?
Orchestration for seamless stretch virtual networks and policies
SDN products:
• Cisco ACI
• VMware NSX
• Juniper Contrail