Cisco IS-IS Local Unequal Cost Multipath

The Segment Routing—IS-IS UCMP feature allows you to load balance outgoing traffic across all IGP ECMP paths proportionally to the interface bandwidth.

Configuring Per-Interface Per-Cause Punt Policer

The per-interface per-cause (PIPC) punt policing is an enhancement to the punt policing and monitoring feature that allows you to configure the limit on traffic per interface. Starting from the Cisco IOS XE 17.5.1 release, you can set the per-interface per-cause rate for all the control plane punted traffic. This rate causes any traffic beyond the set limit to be dropped, therefore allowing you to control the traffic during conditions such as L2 storming.

Configuring ERSPAN

The Cisco DNA Traffic Telemetry Appliance supports the Encapsulated Remote Switching Port Analyzer (ERSPAN) feature on both source and destination ports. ERSPAN transports mirrored traffic over an IP network. You can configure the network devices to mirror traffic on specific ports or VLANs and send it over to the EA Telemetry Sensor for Deep packet inspection. The EA Telemetry Sensor receives and processes data from a port that is configured as ERSPAN.

Capability to limit IPv6 Mroutes per VRF

This feature lets you configure a limit to the number of mroutes on an interface. By limiting the mroutes, you can avoid the risk of flooding the network with mroutes therefore protecting the router from resource overload and also preventing DoS attacks.

Configuring EVPN VXLAN External Connectivity

You can configure the EVPN VXLAN external connectivity for enterprise routers. External connectivity refers to the movement of Layer 2 and Layer 3 traffic between an EVPN VXLAN network and an external network. This enables the EVPN VXLAN network to exchange routes with the externally connected network.

Segment Routing Flexible Algorithm with IS-IS: Segment Routing Flexible Algorithm allows operators to customize IGP shortest path computation according to their own needs. An operator can assign custom SR prefix-SIDs to realize forwarding beyond link-cost-based SPF. As a result, Flexible Algorithm provides a traffic engineered path automatically computed by the IGP to any destination reachable by the IGP. This release also introduces support for the following functionalities:

• Flex Algo prefix metric: Flex-algo prefix-metric allows to associate metric computed in given flex-algo with a prefix during prefix inter-level leaking or during inter-domain redistribution .This help to compute optimal inter-level or inter-domain path Support for affinities include any/all: Ability to pick and choose the links that they want. User can use a certain path without creating a label stack by using the Prefix SIDs or Adjacency SIDs.

• TI LFA + uLoop Avoidance: Allows computation of Loop Free Alternate (LFA) paths. TI-LFA backup paths using the same constraints as the calculation of the primary paths for Flexible Algorithms, for IS-IS Inter-area leaking of Flexible Algorithm SIDs and prefixes and selectively filtering the paths that are installed to the MFI are also supported.

License Management for Smart Licensing Using Policy, Using Cisco vManage

Cisco SD-WAN operates together with Cisco SSM to provide license management through Cisco vManage for devices operating with Cisco SD-WAN. For this you have to implement a topology where Cisco vManage is connected to CSSM.

For information about this topology, see the Connected to CSSM Through a Controller, and to know how to implement it, see the Workflow for Topology: Connected to CSSM Through a Controller sections of the Smart Licensing Using Policy for Cisco Enterprise Routing Platforms guide.

For more information about Cisco vManage, see the License Management for Smart Licensing Using Policy section of the Cisco SD-WAN Getting Start Guide.

For a more detailed overview on Cisco Licensing, go to cisco.com/go/licensingguide

Support for 25G Interface

The ASR 1000 now supports an interface speed of 25G to prevent a single interface causing bottle necks to the overall performance of the router.

Traffic Steering by Dropping Invalid Paths

If the SR-TE Policy has no valid paths defined, the paths are dropped and traffic being steered through the policy falls back to the default (unconstrained IGP) forwarding path. Also, when a SR-TE policy carrying best-effort traffic fails, traffic is re-routed and this impacts the SLA for premium traffic.To solve this issue, if the SR-TE policy fails, the traffic in the data plane is dropped but kept in the controlplane. Therefore, other SR policies, potentially carrying premium traffic, are not impacted.

You can now use the tunnel mpls-ip-only command to configure how the Do Not Fragment bit from the payload is copied into the tunnel packets IP header. If the Do Not Fragment bit is not set, the payload is fragmented if an IP packet exceeds the MTU set for the interface.

You can now view the traffic counters of SR-TE policies using the show segment-routing traffic-eng policy command.

The existing command show segment-routing traffic-eng policy is improved to display the traffic rate on the tunnel interface​. No configuration is required to enable this feature.

Secure forking for non-secure flow in CUBE

Before Cisco IOS XE Bengaluru 17.5.1, Media Proxy supported nonsecure forking of nonsecure calls for both SIPREC and proprietary CUCM and secure forking of secure calls for proprietary CUCM. From Cisco IOS XE Bengaluru 17.5.1, proprietary CUCM supports a combination of secure and nonsecure forking and SIPREC supports secure forking of nonsecure calls using Media Proxy. The configured dial peers can be all secure, all nonsecure, or a combination of secure and nonsecure. The total number of recorders permitted is five. The first secure dial peer is used to set up the B2B call leg. The behavior in Cisco IOS XE Bengaluru 17.4.1 and earlier releases continues if there are no secure dial peers configured. You can use the media-recording proxy secure command to configure secure dial peers.