Cisco Cisco Prime Network Services Controller Adaptor for DFA White Paper

 

 

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A major difference between the distributed gateway technology in Cisco DFA and anycast Hot Standby Router 

Protocol (HSRP) or traditional other First-Hop Redundancy Protocols (FHRPs) such as HSRP, Virtual Router 

Redundancy Protocol (VRRP), and Gateway Load Balancing Protocol (GLBP) is the absence of a hello exchange 

between the various leaves participating and serving the same virtual IP address. Each Cisco DFA leaf provides 

the same gateway MAC address and IP address for a given subnet. 

Interconnection of a Cisco DFA fabric to external networks is achieved through specified leaf switches operating as 

border leafs that peer with external standard unicast and multicast routing protocols. Advanced protocols such as 

Cisco Locator/ID Separation Protocol (LISP), Multiprotocol Label Switching (MPLS), Virtual Private LAN Services 

(VPLS), and Cisco Overlay Transport Virtualization (OTV) are all supported by the Cisco Nexus 7000 Series as 

well as the Cisco Nexus 7700 Series and can be connected to the border leaf for extending the Cisco DFA fabric or 

adding additional functionality. 

The Cisco Nexus 7000 Series, Cisco Nexus 7700 Series, and Cisco Nexus F3-Series I/O modules offer a 

comprehensive solution to combine the border leaf as well as advanced protocol support within a single switch. 

Virtual fabrics offer logical fabric isolation and segmentation within the fabric, extending the boundaries of 

segmented environments to different routing and switching instances. All these technologies can be combined to 

support host, cloud, and multitenancy environments. 

Cisco DFA with its virtual fabrics supports VLAN scaling beyond the 4000-VLAN space traditionally offered by the 

12 bits IEEE 802.1Q header in an Ethernet frame (Figure 2). By extending the traditional header value within the 

fabric, Cisco DFA has a 24 bit name space to uniquely address routing instances (VRF) and fabric global bridge 

domains (logical Layer 2 domains such as VLANs). This extended name space is achieved by Segment-ID. 

Figure 2.    Segment-ID