Latest News about Cisco Technology
December 21, 2024
Labels, Filters, and Subjects Label, filter, and subject managed objects enable mixing and matching among EPGs and contracts so as to satisfy various applications or service delivery requirements. Contracts can contain multiple communication rules, and multiple EPGs can both consume and provide multiple contracts. Labels control which rules apply when communicating between a specific pair
READ MOREVTEP Peer Discovery and Authentication Prior to MP-BGP EVPN, VXLAN didn’t have a control-protocol-based VTEP peer-discovery mechanism or a method for authenticating VTEP peers. These limitations present major security risks in real-world VXLAN deployments because they allow easy insertion of a rogue VTEP into a VNI segment to send or receive VXLAN traffic. With the
READ MORELocal and Remote End-Host Learning The MP-BGP EVPN control plane provides integrated routing and bridging by distributing both Layer 2 and Layer 3 reachability information for the end host residing in the VXLAN overlay networks. Each VTEP performs local learning to obtain MAC and IP address information from its locally attached hosts and then distributes
READ MOREVXLAN Control Plane The initial IETF VXLAN standard (RFC 7348) defined a multicast-based flood-and-learn VXLAN without a control plane. It relies on data-driven flood-and-learn behavior for remote VXLAN tunnel endpoint (VTEP) peer discovery and remote end-host learning. The overlay broadcast, unknown unicast, and multicast traffic are encapsulated into multicast VXLAN packets and transported to remote
READ MOREVXLAN Overlay Traditional network segmentation has been provided by VLANs that are standardized under the IEEE 802.1Q group. VLANs provide logical segmentation of Layer 2 boundaries or broadcast domains. However, due to the inefficient use of available network links with VLAN use, the rigid requirements on device placement in the data center network, and the
READ MORECisco Overlay Transport Virtualization Cisco Overlay Transport Virtualization (OTV) is a MAC-in-IP method that provides a Layer 2 LAN extension over Layer 2, Layer 3, or label-switched Multiprotocol Label Switching–based networks. OTV provides Layer 2 connectivity between remote network sites by using MAC address-based routing and IP-encapsulated forwarding across a transport network to provide support
READ MORENetwork Virtualization Using GRE NVGRE (Network Virtualization using Generic Routing Encapsulation) is a network virtualization method that creates virtual Layer 2 topologies on top of a physical Layer 3 network. Connectivity in the virtual topology is provided by tunneling Ethernet frames in GRE over IP over the physical network. The purpose is to enable multitenant
READ MOREOverlay Network Protocols Modern virtualized data center fabrics must meet certain requirements to accelerate application deployment and support DevOps needs. For example, fabrics need to support scaling of forwarding tables, scaling of network segments, Layer 2 segment extension, virtual device mobility, forwarding path optimization, and virtualized networks for multitenant support on shared physical infrastructure. Overlay
READ MORESummary This chapter discusses routing fundamentals, configuration and verification of RIPv2, EIGRP, and OSPFv2 unicast routing protocols on NX-OS, multicast fundamentals, and PIMv2 configuration and verification on NX-OS, including the following points: In link-state protocols, also known as shortest path first (SPF), each router builds a link-state advertisement (LSA) that contains information about each link
READ MOREIGMP Snooping The default behavior for a Layer 2 switch is to forward all multicast traffic to every port that belongs to the destination LAN on the switch. This behavior reduces the efficiency of the switch, whose purpose is to limit traffic to the ports that need to receive the data. IGMP snooping efficiently handles
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