Overlay Transport Virtualization (OTV) is a sector technique that enables widening Layer 2 implementations across dispersed data centers a breeze. Without modifying or rearranging the current network design, users nowadays can utilize Data Center Interconnect (DCI) among locations.
Users can use OTV to implement simulated computational power and groupings across globally disparate data centers, resulting in Excessive job mobility that is transparent, Resilience in the workplace, and Outstanding reusing and recycling in calculating. OTV offers unicast and multicast as transports between sites. Let’s take a glance at the distinctions between the two.
Cisco OTV Unicast and Multicast
The main difference between Cisco OTV Unicast and Multicast is OTV can be implemented with unicast transport only. On the other hand, OTV can not be implemented with multicast transport. In some situations, the operational simplicity provided by the unicast-only model may make the configuration alternative very attractive, obviating the requirement for the multicast model.
Cisco OTV Unicast is a transport system between the sites. When the users have a limited number of websites, Cisco OTV unicast is beneficial, and in unicast configuration, the Overlay interface number should be consistent throughout the process. Each OTV device would have to duplicate every network control message and unicast them to all other OTV applications in the same rational base layer.
Cisco OTV Multicast is also a transport system between the sites. When communicating with multiple sites, multicast is the recommended choice due to its versatility and functionality. Due to head-end recombination behavior, implementing OTV over a multicast-enabled transport is still the best option in situations where multiple DC locations are implicated.
Comparison Table Between Cisco OTV Unicast and Multicast
What is Cisco OTV Unicast ?
OTV could be used with unicast transport that operates in the same way as OTV in multicast mode over a unicast-only transport. The only difference here is that every OTV machine would need to duplicate each network control parcel and unicast them to every distant OTV device in the very same coherent overlay. The organizational generalization provided by the unicast-only model (which eradicates the need for multicast implementation) can make this implementation alternative very attractive in situations where LAN enhanced version internet service is needed just between a few DC locations.
Evey access point must have sent a unicast replica of the handled packet to each separate device in unicast mode. The adjacency server feature helps a firewall to discover and disseminate a checklist of network edge devices, ensuring that all OTV website participants were informed of one another. The adjacency algorithm computes a Unicast Replication List (URL) and allocates it with each network edge, adjusting it to as actually required as apps participate or leave the system.
Installing a second web page is as simple as customizing the new machine with the addresses of the two different adjacency data centers, who would then disperse details of the new machine to the remaining portion of the overlay.
What is Cisco OTV Multicast?
While using OTV in multicast mode, the underlying multicast facilities addressed message copying to every one of the distant OTV machines, as well as a vibrant revelation of OTV peer group.
When IP multicast is accessible in the network infrastructure, the OTV Adjacency Server feature is not suggested for implementation. Because of its extensibility and lower bandwidth when attempting to communicate with multiple websites, multicast is the favored transportation. A non-IANA multicast MAC address is allotted a unicast IP address in multicast mode. Because IGMP surveillance does not adaptively program the above location, the NLB traffic in the VLAN floods.
When using NLB in multicast configuration, the NLB supplies the ARP server receives packets data with an IP address, but the MAC network system is a multicast MAC address. The MAC address of the user’s network interface card (NIC) is the origin MAC address of the periphery (Layer 2) header. However, the sender MAC address (internal ARP button) is the cluster’s multicast MAC address.
To use NLB in multicast mode all over webpages in OTV, the users must deactivate or disable OTV’s standard ARP local cache management behavior. And, the user should keep in mind that for multicast-mode OTV, the core of the system must be multicast conscious.
Main Differences Between Cisco OTV Unicast and Multicast
- Cisco Unicast OTV is supported by Cisco Nexus 7000 Series switches at one site, while Cisco Multicast OTV is supported by Cisco ASR 1000 Series switches at both sites.
- Cisco Unicast OTV continues to work well with two or three sites, whereas Cisco Multicast OTV can interact with various sites simultaneously.
- Cisco Unicast OTV is less flexible for the transportation of websites, whereas Cisco Multicast OTV is a more flexible and strong kind of transportation of websites.
- Cisco Unicast OTV mode allocates a virtual IP and MAC address to the cluster, whereas Cisco Multicast OTV mode assigns a unicast IP address to a non-IANA multicast MAC address.
- Cisco Unicast OTV causes high traffic while dealing with more than two websites, whereas Cisco Multicast OTV doesn’t cause any traffic.
Conclusion
When IP multicast is not accessible in the network infrastructure on which Overlay Transport Virtualization (OTV) keeps running, the OTV Adjacency Server feature allows users to develop unicast-only transport among network edge systems. The OTV management plane serves the same purpose with unicast-only transport as it does with a multicast core.
Both the OTV works almost the same as a means of transport among sites. When interacting with various websites, multicast is the main mode of transport due to its versatility and lower operational system. If the user needs only need two or three sites, unicast will be enough without sacrificing any functionalities.
References
- https://www.researchgate.net/profile/Usman-Dar-4/publication/325716317_Considerations_in_Designing_DCI_Data_Centre_Interconnect_in_Full_Mesh_VPLS_Multicast_Enable_WAN_over_OTV_Tunne/links/5ec42a5d92851c11a8777371/Considerations-in-Designing-DCI-Data-Centre-Interconnect-in-Full-Mesh-VPLS-Multicast-Enable-WAN-over-OTV-Tunne.pdf
- https://www.researchgate.net/profile/Syed-Measum-Haider-Bokhari/publication/309739191_Overview_and_Design_Of_Overlay_Transport_Virtualization/links/582154ac08aea429b29c0441/Overview-and-Design-Of-Overlay-Transport-Virtualization.pdf