Cisco Catalyst 9000/9800 Series Switch: Настройка локальной Bonjour в режиме уникаста для LAN-сетей (EN)

Prerequisites for Local Area Bonjour in Unicast Mode for LAN Networks

Configuring Local Area Bonjour in Unicast Mode for LAN Networks Cisco Catalyst 9000 Series switches and Cisco Catalyst 9800 Series WLC introduce the unicast mode function in Local Area Bonjour network domain. The new enhanced gateway function at the first hop of wired and wireless networks communicates directly with any industry standard RFC 6762 compliant mDNS end point in Layer 2 unicast mode. The new unicast mode communication eliminates the Layer 2 mDNS flood challenge in large-scale enterprise-grade LAN and WLAN networks. The unicast mode provides enhanced security, bandwidth, scale, and performance within the network.

Prerequisites for Local Area Bonjour in Unicast Mode for LAN Networks, on page 1 Restrictions for Local Area Bonjour in Unicast Mode for LAN Networks, on page 2 Information About Local Area Bonjour in Unicast Mode for LAN Networks, on page 2 Configuring mDNS Gateway Mode, on page 6 Configuring mDNS Service Policy, on page 9 How to Configure Local Area Bonjour Unicast Mode for LAN Networks, on page 12 Verifying Local Area Bonjour in Unicast Mode for LAN Networks, on page 22 Additional References for Local Area Bonjour in Unicast Mode for LAN Networks, on page 24 Prerequisites for Local Area Bonjour in Unicast Mode for LAN Networks You must ensure that the Cisco Catalyst devices are successfully configured and are operational prior to implementing Cisco Local Area Bonjour in unicast mode for LAN networks.

The following are the prerequisites that need to be verified on a Cisco Catalyst Switch before deploying it in SDG-Agent mode or Service-Peer mode: • Verify that the targeted Cisco Catalyst switch platform is supported in SDG-Agent or Service-Peer mode from the support matrix. • Verify that the targeted Cisco Catalyst SDG-Agent and Service-Peer switch are running the minimum required Cisco IOS XE software version. • The Cisco Catalyst switch in SDG-Agent and Service-Peer mode must have the valid Cisco DNA Advantage license installed and running. Configuring Local Area Bonjour in Unicast Mode for LAN Networks 1

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Information About Local Area Bonjour in Unicast Mode for LAN Networks

• In a Multilayer network with Layer 2 unicast service-routing, ensure that the SDG-Agent in distribution-layer and Service-Peer is interconnected through a Layer 2 trunk in static mode. • Ensure that the SDG-Agent and Service-Peer switches have IP reachability on the same IPv4 subnet in global routing. Restrictions for Local Area Bonjour in Unicast Mode for LAN Networks • Local Area Bonjour in Unicast Mode for LAN Networks is not supported on Cisco Catalyst 2900 Series, Cisco Catalyst 3850 Series, Cisco Catalyst 3650 Series, Cisco Catalyst 4500 Series, Cisco Catalyst 6500 Series, and Cisco Catalyst 6800 Series switches.

• Cisco SD-Access for wired and wireless networks is supported only for releases starting from Cisco IOS XE Amsterdam 17.3.3. • Cisco Embedded Wireless Controller on a Cisco Catalyst Series switch is supported only for releases starting from Cisco IOS XE Amsterdam 17.3.3. • The Cisco Bonjour gateway solution follows the industry standard RFC 6762 Multicast DNS (mDNS) guidelines and only supports wired or wireless end points that comply with unicast mode. • The Catalyst Switch Management Port is not supported for local area service-routing. • mDNS doesn't support the split of transport with dual stack on FHRP between SDG agents.

You can either enable IPv4 or IPv6 management VLAN and make one switch as FHRP active. • You can configure either Local Area Bonjour in Unicast Mode or Local Area Bonjour in Multicast DNS mode, and not both, on the same SDG agent or the same service peer. • Beginning from Cisco IOS XE Cupertino 17.9.1, if autostate is disabled on a switch virtual interface (SVI), cache records will not be updated. To update the cache records, autostate must be enabled on the SVI.

Information About Local Area Bonjour in Unicast Mode for LAN Networks The zero-configuration service discovery and distribution capabilities use the link-local mDNS protocol to discover rich services intuitively without extensive user knowledge and intervention. RFC 6762 provides guidelines to discover services via Layer 2 multicast or Layer 2 unicast in a local segment. The receiving end point may request service discovery over an IPv4 and IPv6 network to collect information prior to use. The Layer 2 multicast frames are broadcast-category packets in a LAN and WLAN environment. Thus, they are flooded based on the Layer 2 flood boundary size across the network.

The Layer 2 or Layer 3 network boundary varies broadly in an enterprise network for LAN and wireless designs. The Local Area Bonjour domain introduces two new unicast communication modes. The unicast communication modes prevent mDNS flooding in the network for any current or evolving network deployment models. The following are the two new aspects of Local Area Bonjour Unicast modes: Configuring Local Area Bonjour in Unicast Mode for LAN Networks Restrictions for Local Area Bonjour in Unicast Mode for LAN Networks Configuring Local Area Bonjour in Unicast Mode for LAN Networks 2

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Layer 2 Network for Unicast Mode

• Unicast mode end points • Unicast mode Layer 2 network End Points for Unicast Mode Starting with Cisco IOS XE Amsterdam Release 17.3.2, Cisco Catalyst 9000 Series switches and Cisco Catalyst 9800 Series WLCs introduce Layer 2 unicast service gateway solution. The mDNS endpoint continues to advertise or query services over Layer 2 mDNS. However, with the unicast mode settings enabled, the incoming mDNS IPv4 and IPv6 frames are handled uniquely. The unicast technique eliminates the mDNS flood challenges and provides a policy-based service query response to the requesting end points over a unicast MAC address.

The following figure illustrates the functional difference between the new Layer 2 unicast (flood-free) and the traditional Layer 2 Multicast (flood) communication with wired and wireless end points. Figure 1: Layer 2 Unicast Mode End Points Layer 2 Network for Unicast Mode The Layer 3 boundary for wired and wireless networks can reside in the distribution layer with Layer 2 connections extended over trunk ports to an access layer switch or WLC. The association of the nonpruned or common VLAN ID to the trunk ports extends the Layer 2 flood boundary across the network.

Starting with Cisco IOS XE Amsterdam Release 17.3.2, Cisco Catalyst 9000 Series switches and Cisco Catalyst 9800 Series WLCs introduce the Service Peer role to eliminate transmitting mDNS flood over trunk ports. The Service Peer establishes a unicast Layer 3 IPv4-based service-routing session with the distribution layer system in Service Discovery Gateway (SDG) role. The Service Peer establishes the session over the existing Layer 2 trunk ports without modifying any existing Layer 2 VLAN configuration.

The new mDNS trust port between access layer and distribution layer uses the existing out-of-band management network to statefully discover and distribute services (based on policies) to replace traditional flood-n-learn methods from the Layer 2 network. If the Layer 3 boundary in a LAN environment is at the access layer, then the SDG mode provides integrated Service Peer role. Further, the SDG mode needs only Wide Area Bonjour with Cisco Catalyst Center for service-routing in a Layer 3 IP network. The following figure illustrates a Layer 2 Network with the unicast mode and a traditional Layer 2 network with mDNS flood:

Configuring Local Area Bonjour in Unicast Mode for LAN Networks End Points for Unicast Mode Configuring Local Area Bonjour in Unicast Mode for LAN Networks 3

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HSRP-Aware mDNS Service-Routing

Figure 2: Unicast Mode Layer 2 Network Default mDNS Service Configurations Starting with Cisco IOS XE Bengaluru 17.6.1, an intuitive approach to configuring mDNS services, known as the default mDNS service configuration, is introduced. The default service configuration contains a default service policy that creates a service list with default service-types that is automatically enforced in the ingress or egress direction. The following figure illustrates the default mDNS service configurations: Figure 3: Default mDNS Service Configuration The default mDNS service configurations accelerates solution adoption, increases user productivity, and reduces operation overhead.

Additionally you can define a custom policy and define a service list with custom-defined service types and enforce it in the ingress or egress direction. HSRP-Aware mDNS Service-Routing Starting from Cisco IOS XE Bengaluru 17.6.1, Hot Standby Router Protocol-aware (HSRP-aware) mDNS Service-Routing is supported between Service Peers and SDG agents in a multilayer network. During a changeover, that is when the primary SDG agent fails and the secondary SDG agent becomes the new primary, the service-routing session between the Service Peer and the SDG agent remains uninterrupted. The new primary SDG agent establishes a session with the Service Peer and cache information is resynced.

Configuring Local Area Bonjour in Unicast Mode for LAN Networks Default mDNS Service Configurations Configuring Local Area Bonjour in Unicast Mode for LAN Networks 4

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