• Author : Anoop

 
 

Bidirectional PIM

Bidirectional Protocol Independent Multicast (PIM) allows routers to build trees to deliver multicast traffic from sources to receivers. It is a variant of sparse-mode PIM that efficiently addresses the use case where receivers for a  multicast group are also sources for that group. While sparse-mode PIM builds shared trees and source specific trees, bidirectional PIM only builds shared trees. A shared tree for a multicast group is rooted at the Rendezvous Point (RP) for that group. The RP for a bidirectional group is an IP address, which may or may not be real, but is reachable via all routers in the multicast...
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Static Multicast

Static multicast feature brings in capability to statically configure multicast routes on any Arista platform running this release of software. This feature must be viewed independently of PIM-SM and PIM-BIDIR protocols which are dynamic variants of programming multicast routes. The feature has been designed to co-exist with these protocols. While the feature is designed to co-exist with dynamic protocols, the selection method for routes are to be kept in mind before programming static routes in order to get predictable results. Static multicast routes competes with the routes provided by PIM-SM and PIM-BIDIR mainly because this static variant, allows the operator...
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PBR Support on Arista 7050X/7250X/7160/7300X

Policy Based Routing (PBR) provides the flexibility of routing according to custom defined policies in a way that goes beyond traditional routing protocol concerns. By using policy-based routing, customers can implement policies which can selectively cause packets to take paths different from the paths decided by routing protocols. Platform compatibility DCS-7050X DCS-7300X DCS-7250X DCS-7160 Configuration Arista supports a CLI model where a QoS-style policymap/classmap will be used for the PBR feature. In addition to matching on regular ACL, the PBR policymap can also include a ‘raw match’ statement that looks like a single entry of an ACL. The action part...
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IPv6 nexthop group support in EOS

Nexthop groups in EOS currently only support IPv4 entries and only IPv4 routes can point to nexthop groups. This feature relaxes both these constraints wherein we can have IPv6 entries in the nexthop group and have IPv6 routes pointing to nexthop groups. This constraint is only removed for MPLS nexthop groups on the 7500E and 7280 series. For a given nexthop group, the address family for the entries within it cannot be mixed, i.e. all entries are either of IPv4 address family or of IPv6 address family. Similar to IPv4 entries, the IPv6 entries will get recursively resolved to an immediate...
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Secondary private VLAN trunk ports

Secondary private VLAN trunk ports are introduced in the EOS-4.15.2F release. This feature can be enabled via a new command under interface configuration mode (for details please refer to section “Configuration command” below). Please note that this command is only applicable to trunk ports. When configured, this feature allows the extension of a secondary VLAN (both isolated and community) through a non-private VLAN aware switch. When private VLAN mapping is configured on a trunk port, egress mappings are added on the trunk port for all (primary VLAN id, secondary VLAN id) pairs. Since we can only allow for one such mapping for a given primary VLAN id, if there are multiple secondary VLANs configured...
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Agile Port Platform Command

Introduction This article describes changes to the platform command ‘show platform fm6000 agileports’. Earlier this command was ‘show platform fm6000 agileport map’ which displayed only the mapping between the agile port and the subsumed interfaces. The command did not list information about the agile port configuration or interface status. This information is now available in the output of the ‘show platform fm6000 agileports’ command. eAPI support for this command is available. Platform compatibility DCS-7150S Configuration In order to view the updated output of the platform command, consider the following configuration where Ethernet1 is configured as an Agile port using the interface command...
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Tapagg Group Information

Introduction This article describes the addition of a show command to display the mapping between tap and tool ports on a per tap/tool port basis. The command displays the active tap/tool ports by default but offers a ‘configured’ keyword option to view configured tap/tool ports. The output lists the tap agg policy map or class map that is used to map a tap port to a tool port. The output list is sorted first on the tap port, then on the policy/class name, then the group name and lastly on the tool port name. Platform compatibility DCS-7150S DCS-7280SE DCS-7500E Show...
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Hardware Table Capacity Monitoring

Hardware Table Capacity Monitoring is a new feature to keep track of the capacity and utilization of various hardware forwarding resources and generate alerts/syslogs when the utilization exceeds a threshold value. Users can keep track of the current usage statistics using a single show command, and also configure thresholds on a per-resource basis, to be notified about any high-utilization upfront, before reaching any resource limits. The Main use-case would be for troubleshooting in overflow situations and avoid overflows altogether by taking corrective actions on high utilization. Platform compatibility DCS-7280E DCS-7500E DCS-7160-32CQ DCS-7160-48YC6 DCS-7160-48TC6 Configuration The concept of threshold is used...
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Recirculation Channel

Some data-plane features on some switch platforms may require packets to be recirculated through the switch chip in order to implement configured features and functionality. VXLAN Routing on Arista 7050X Series (single-chip T2) is one such feature. Recirc-Channel interfaces are a logical grouping of Ethernet and UnconnectedEthernet interfaces for use in recirculating the packet to provide features that require recirculation.  Each Recirc-Channel is tied to one specific feature. In this release, the only feature to be used in conjunction with Recirc-Channel interfaces is VXLAN Routing on Arista 7050X series devices. Platform compatibility DCS-7050X series Configuration The configuration for Recirc-Channel interfaces...
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LANZ

Introduction LANZ on DCS-7280SE and DCS-7500E adds support for monitoring congestion on front panel ports at a more granular level with Start, Update, and Stop congestion events. These events are available while using Notifying mode. The previous behavior of polling the most congested queue per ASIC is still available in the default Polling mode. LANZ Streaming is now available on DCS-7280SE and DCS-7500E. Platform compatibility DCS-7280SE DCS-7500E Configuration Enabling Notifying mode Arista(config)# queue-monitor length notifying This enables Notifying mode. The default is Polling mode. In a mixed system with both DCS-7500 and DCS-7500E linecards configuring Notifying mode results in Notifying mode on DCS-7500E cards...
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Fabric QoS on 7250X and 7300X

The 7250X and 7300 series use an optimized internal CLOS design with multiple port ASICs interconnected via Fabric ASICs in an efficient non-blocking two-tier design. Starting EOS 4.15.2F, EOS allows configuring QoS on fabric ASICs on these platforms. Configuring QoS on the fabric ASICs in addition to front panel ports empowers users to have end-to-end control on these platforms. By default, queues are configured as strict priority on 7250X and 7300X series. The following configuration options are now supported on fabric interfaces: Guaranteed Bandwidth: In order to prevent queue starvation on fabric ports EOS supports minimum bandwidth configuration on per queue basis across all fabric...
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VXLAN multicast decapsulation

VXLAN multicast decapsulation enables VTEPs that only support HER (Head End Replication) to terminate multicast encapsulated BUM(Broadcast/Unknown/Multicast) packets from remote VTEPs that do not support HER. Platform compatibility DCS-7050X DCS-7250X DCS-7300X Configuration The feature is enabled by using the below CLI under interface Vxlan: Arista(config-if-Vx1)#vxlan multicast-group decap 230.1.1.1 The above command can take more than one multicast group. To disable the feature use the ‘no’ option under interface VXLAN and specify the groups that need to be disabled: Arista(config-if-Vx1)#no vxlan multicast-group decap 230.1.1.1 Status Use the following show command to verify that the multicast group is configured for decapsulation in...
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Automatic MLAG ISSU Compatibility Detection

This feature detects whether a given EOS image is MLAG ISSU compatible with the currently running version on a switch. If the given new image is found to be incompatible then all EOS versions which are potentially compatible to both the given EOS image and the currently running image are listed. Also this adds support to generate additional Mlag ISSU compatibility warnings while reloading the switch or while issuing ‘show mlag issu warning’ command. All the EOS images has an Mlag ISSU Compatibility matrix published as part of the Release Notes. This matrix shows which images are compatible to a...
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Routing adjacency across VRFs with external physical loopback

This feature allows routing traffic across two Vrf domains on the same switch using an external loopback cable connecting ports in different Vrf domains. If a packet received in Vrf1 is forwarded to the interconnect port (either by static route or by default route), the packet is received back in Vrf2 on the same switch. This packet is then forwarded using Vrf2 routing table. Platform compatibility DCS-7300X (TBD: Trident based platforms) DCS-7250X (TBD: Trident based platforms) DCS-7500E Configuration There are no new CLI for configuring or enabling this feature. Here is the example configuration for the topology shown below: An interconnect...
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Static IPv4 routes with IPv6 next hops

This feature enables configuring static IPv4 routes that specify the next-hop by using an IPv6 address instead of an IPv4 address. IMPORTANT:  This is not intended to be a customer-used feature in this release, but is rather the first part of a follow-on feature in a subsequent release.  As such, the feature-specific CLIs are currently hidden.  This TOI exists to document the feature “just in case”. Platform compatibility This feature is supported on all platforms. Configuration To configure the feature, simply specify an IPv6 address instead of an IPv4 address when creating a static route in configuration mode. Arista(config)#ip route 10.0.0.0/8 a::1...
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Vxlan Routing

  VxLAN bridging enables stretching Layer 2 domains across a Layer 3 cloud. VxLAN routing provides the capability to route between these Layer 2 domains. On the 7050X, 7060CX, and 7260QX series, VxLAN routing is achieved by recirculating the packet multiple times through the ASIC. The routing action (which involves a L2 header rewrite), the VxLAN tunnel decapsulation action, and the VxLAN tunnel encapsulation action each requires a pass through the ASIC. The recirculation is achieved by MAC loopback on dedicated loopback interfaces. Platform compatibility The platforms with the EOS version where the feature was introduced: DCS-7050X series EOS-4.15.2F DCS-7060CX...
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v4 NLRI over BGPv6 transport

This feature enables exchanging IPv4 NLRI using MP-BGP over an IPv6 TCP connection.  Additionally, this feature adds a new configuration keyword, “auto-local-addr” which instructs the router to automatically determine what address to use as the next hop on these NLRIs, instead of requiring manual configuration. Platform compatibility The feature is supported on all platforms. Configuration All commands listed here are used in BGP configuration mode, either for the default VRF or for a non-default VRF. To enable IPv4 NLRIs over an IPv6 connection, an IPv6 neighbor must be activated in the IPv4 address family. This can be done explicitly on a...
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IS-IS BFD (IPv4 only)

Bidirectional Forwarding Detection(BFD) is a low overhead protocol designed to provide rapid detection of failures in the path between adjacent forwarding engines over any media and at any protocol layer.  This document describes the procedures for configuring BFD support for IS-IS for IPv4. As of EOS-4.15.XF BFD is supported for ISIS-IPv4 routes. Configuration Following commands are used to configure BFD over IS-IS. [ no ] bfd all-interfaces : This command enables/disables BFD for all the interfaces on which IS-IS is enabled. It can be overridden with the interface specific CLI. By default BFD is disabled on all the interfaces. Arista(config)#router isis 1      ...
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Arista EOS-4.15.2F transfer of information

Arista Platform Independent Features IS-IS Level-1-2 Router IS-IS full MD5 IS-IS IPv4 BFD IS-IS IPv6 VRF IS-IS attach-bit IS-IS Multi-Topology IS-IS SPF Timers IS-IS wait-for-BGP IS-IS hostname IPv4 NLRI over BGPv6 transport BGP NSF OSPFv3 enhancements BGP sFlow export of ECMP information BGP best path selection improvements Static IPv4 routes with IPv6 nexthop BGP recursive route resolution with nexthop groups BGP add-path RX Routing adjacency across VRFs with external physical loopback Maintenance Mode OpenFlow/DirectFlow enhancements PIM VRF Bidirectional PIM Automatic MLAG ISSU Compatibility Detection Tunable SFP BGP selective route download BGP neighbor max-routes needs restart interval config option MLAG config check...
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OSPFv3 authentication

This feature adds authentication support for OSPFv3. Unlike OSPFv2, OSPFv3 does not have authentication fields in the packet header. It requires IPv6 Authentication Header (AH) and IPv6 Encapsulating Security Payload (ESP) to provide integrity, authentication or confidentiality. To configure authentication, Security Association needs to be configured from the cli which has two parameters: Security Policy Index (SPI) and a secret key. These parameters are used to compute an Integrity Check Value (ICV), which is used to authenticate peers. For the OSPFv3 to work between a set of peers with authentication enabled, SA parameters must be same for all of them. OSPFv3 packets received over an interface...
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