• Tag : 4.21.0F

 
 

MACsec Bypass for LLDP

A MACsec port with this feature enabled transmits LLDP frames without MACSec encryption and receives LLDP frames with or without MACsec encryption.  This feature allows intermediary non-MACsec devices between MACsec peers to be able to process the LLDP frames from MACsec devices. Platform compatibility DCS-7280CR2M-30 DCS-7280SRAM-48C6 DCS-7280SRM-40CX2 DSC-7500R-8CFPX-LC DCS-7500RM-36CQ-LC DCS-7500R2M-36CQ-LC Configuration By default this feature is disabled and it needs to be explicitly added in the mac security profile for the corresponding MACsec port to enable it.  Please note that et49_1 is the name of the mac security profile in the following examples. 7280(config-mac-security-profile-et49_1)#l2-protocol lldp bypass To disable this feature:...
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Coherent PHYs and Optics

Updates Specific to EOS 4.21.0F and Subsequent Releases Note: EOS 4.21.0F and subsequent releases may require manual updates to frequency or channel and grid spacing in the configuration sections for interfaces that utilize tunable (non-SFP+) form factor transceivers. EOS 4.21.0F and subsequent releases errdisable interfaces utilizing a tunable (non-SFP+) form factor transceiver by default. Removing the errdisabled condition from an interface requires specifying an explicit, valid tuning frequency configuration for the interface. The following TOI is an extension of the Coherent PHYs and Optics TOI here: https://eos.arista.com/eos-4-17-0f/coherent-phys-and-optics/ Configuration Enhancements for configuring frequency/wavelength Note: These enhancements do not affect 10GBASE-DWDM SFP+...
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ASU Auto-patch

Description ASU allows a user to upgrade the switch to a newer software release with minimal downtime (no traffic loss). In some cases we need to make fixes/changes to the currently deployed software release running on the switch before proceeding with ASU. Previously, this was achieved by providing patches which had to be manually installed, on each switch requiring the changes, and in some cases different patches were required depending on the current EOS version running on each switch. In order to avoid this cumbersome effort, Arista has developed ASU Auto-patch. ASU Auto-patch is a software feature that will remove...
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QinQ L3 Subinterfaces

QinQ L3 subinterfaces divide a single ethernet or port-channel interface into multiple logical L3 interfaces based on a combination of two 802.1q tags (VLAN ID) in the incoming traffic. QinQ L3 subinterfaces are commonly used in the L2/L3 boundary device, but they can also be used to isolate traffic with a combination of two 802.1q tags between L3 peers by assigning each subinterface to a different VRF. QinQ L3 subinterfaces are similar to regular L3 subinterfaces, with the only difference being the number of tags being used to isolate traffic. While L3 subinterfaces use a single 802.1q tag (VLAN ID)...
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BGP Conditional Route Inject (Routing protocol mode Rib)

Introduction BGP Conditional route inject provides the capability to control BGP advertisements based on certain conditions in the System. This is achieved using “Dynamic prefix-lists” policy type. Dynamic prefix-list policy construct is similar to the traditional IP and IPv6 prefix-list, except that they have an additional state associated. This state associated with the dynamic prefix-lists, is determined on the basis of the route entries in FIB, and hence as and when the FIB changes, the state also changes dynamically. This state determines the dynamic prefix-list behavior, when used in route-map match clauses etc. Dynamic prefix-list can be used to: 1. Conditionally advertise/withdraw set of...
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Segment Routing Traffic Engineering Policy (SR-TE)

Description Segment Routing Traffic Engineering Policy (SR-TE) aka SR Policy makes use of Segment Routing (SR) to allow a headend to steer traffic along any path without maintaining per flow state in every node. A headend steers traffic into an “SR Policy”. EOS 4.21.0F adds support for SR Policy for the MPLS dataplane (SR-MPLS) for Type-1 SR Policy segments with BGP and locally configured policies as sources of SR Policies on Arista’s 7500, 7280 families of switches. SR Policy Overview SR Policy identification An SR Policy is identified using a 2-tuple of Endpoint – an IPv4 or IPv6 address which...
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CFP2-DCO configuration, status and troubleshooting

Background DCS-7280SRM-40CX2 (see picture below), is a 1RU fixed system, which has two CFP2 ports (41 and 42), capable of hosting either CFP2-DCO, or standard CFP2-100G-LR4/ER4 modules. CFP2-DCO modules integrate the coherent DSP into the pluggable module.   Main features of DCS-7280SRM-40CX2 CFP2-DCO modules: capable of delivering up to 200G per port over distance beyond 1200 km. DP-QPSK (100G), DP-8QAM (200G) and DP-16QAM (200G) modulation formats are supported. Soft decision FEC, with a high net coding gain, is used to enhance data reliability.   Interoperable with another DCS-7280SRM-40CX2 CFP2-DCO, or with 7500R-8CFPX-LC linecard with CFP2-ACO optics. Configuration Modulation The “phy coherent-dsp...
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Coherent Forward Error Correction

Coherent signaling technology is used for data transmission over long distances. These transmitted signals are highly susceptible to degradation. Forward Error Correction (FEC) helps in protecting data integrity over these long distances by recovering the degraded signal at the receiver using parity data that is piggy backed in the transmitted signal.   Platform compatibility : 7500R-8CFPX-LC 7280SRM-40CX2 with CFP2-DCO transceivers installed Coherent FEC algorithms supported:    Most of these coherent FEC algorithms are vendor proprietary, although some may be industry standard. Soft Decision FEC with 15% overhead (SD-15%) Soft Decision FEC with 20% overhead (SD-20%) Soft Decision FEC with 25%...
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Segment Security

The Segment security feature provides the convenience of applying policies on segments rather than interfaces or subnets. Workloads/VMs are classified into segments based on interfaces, subnets, and ip addresses. Grouping interfaces and subnets into segments allows for definition of policies between segments that govern flow of traffic between them. Policies define inter segment communication rules, e.g. segment A can communicate with segment B over tcp port 80 . By default no communication is allowed between segments. Explicit rules need to be configured to allow communication. Communication between workloads within the same segment is not restricted. This feature is similar to...
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Lanz Mirroring

Description Lanz Mirroring feature allows users to automatically mirror traffic queued as a result of congestion to either CPU or a different interface. Platform compatibility 7150S-64 7150S-52 7150S-24 7050QX-32 7050QX-32S 7050SX-72Q 7050SX-64 7050SX-72 7050SX-96 7050SX-128 7050TX-48 7050TX-64 7050TX-72 7050TX-96 7050TX-128 7050TX-72Q 7060CX-32S 7060CX-32S-ES 7060CX2-32S 7060SX2-48YC6 Configuration Enabling LANZ Mirroring LANZ mirroring is disabled by default. In order to enable LANZ mirroring, LANZ must be enabled. Enabling LANZ mirroring will also reserve one port mirroring session. Arista(config)#queue-monitor length mirrorArista(config)#no queue-monitor length mirrorArista(config)#default queue-monitor length mirror Selecting Destination Interface When congestion occurs on any of the LANZ mirroring source interfaces, the traffic...
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Priority Flow Control ( PFC )

Priority Flow Control is a link-layer flow control mechanism which may be used by an overwhelmed network node to ask its transmitters to stop transmission for a specified period of time. It does so by using special frames known as PFC frames, thus, relieving congestion at the receiver node. With respect to this behaviour, PFC is very similar to Link Layer Flow Control ( LLFC ), however, unlike LLFC, PFC allows the overwhelmed node to specify which 802.1Q Class of Service ( CoS ) it wants to stop receiving traffic for. Thus, allowing differentiated treatment of traffic based on CoS....
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Health Tracker

Introduction Network operators have to monitor all kinds of information on the health of their networking equipment like monitoring failures of fan modules and power supplies, hardware table capacity, cpu usage, etc. As features get added to network equipment the amount of monitoring that needs to be done increases significantly. This feature helps network operators query the health of the system in a single location by providing a layered view of all bad events currently occurring in the system. The set of things to be monitored would continuously be updated over releases and time.The feature uses the ‘event-handler’ infrastructure to...
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BGP Labeled-Unicast (LU) path NH resolution over Tunnel RIB entries

Description Prior to this release, BGP in “ribd” mode (when routing protocols are configured in “ribd” mode) supports resolution of BGP Labeled-Unicast protocol (BGP LU) path next-hop over only connected routes. Resolution of the next-hop over IGP or static routes is not allowed since the next-hop router may not be in the MPLS forwarding path in which case the traffic will get dropped by the next-hop router (per IGP). This enhancement allows BGP in “ribd” mode to support resolution of BGP LU path next-hop over entries in the Tunnel RIB and fall-back to resolving over connected route when there is...
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PHY test pattern CLI

The PHY test pattern CLI can be used to check the quality of the physical layer for an Ethernet interface. This is done by generating a specific test pattern to a peer, and having the peer check the test pattern that is received, and vice versa. Because the test pattern is a well-known sequence of bits, the peer can check that the pattern received matches this well-known sequence; any difference is a bit error introduced by the peculiarities of the physical layer. Quality of the link could be determined based on the acceptable bit errors, as published by the hardware...
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Dhcpv6 Relay agent Client Link Layer Address

Introduction This feature allows Dhcpv6 relay agent to add Client link-layer address option  (specified in RFC 6939) to solicit and request message. This option will help DHCP server to correlate DHCPv6 assignment using the same identifier as the DHCPv4 assignment. Configuration Arista(config)#ipv6 dhcp relay option link-layer address Enables the insertion of link layer address option  (79) in global configuration mode. Arista(config)#no ipv6 dhcp relay option link-layer address Disable the insertion of link layer address option  (79) in global configuration mode. Show Command Arista#show ipv6 helper-address A message indicating the state of client Link Layer Address option is added to the...
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uRPF exceptions

Unicast Reverse Path Forwarding (uRPF) can help limit malicious traffic on a network. uRPF works by enabling the router to verify reachability of the source IP address (SIP) in the packet being forwarded. If the SIP is determined to not be a valid address, the packet is dropped. uRPF works in three different modes, strict mode, loose mode and strict mode with allow-default. In the strict mode, the  packet must be received on  the same L3 interface that the router would use to route the return packet. In the loose mode, the router must have a route configured for the...
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Partition FDB and IPv4 Host Routes

Platform Compatibility: DCS-7160 Description: Host table partitioning provides the ability to change the allocation of MAC and host route tables on a switch. By default, MAC and host route tables share the same hash table. This configuration allows the user to have a dedicated hash table for each of the MAC and IPv4 host route entries.  IPv6 host entries will go into the LPM when this partition occurs. Configuration: The CLI syntax for configuring FDB partitioning is below:   [no] platform xp host-table { dedicated | shared }   Usage example:   switch(config)#platform xp host-table ? dedicated  Dedicated hash tables for...
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Multicast Listener Discovery (MLD)

The MLD protocol is the IPv6 equivalent of IGMP for IPv4. Multicast routers use MLD to find out about multicast receivers on their local networks. A MLD agent periodically queries for listeners interest in receiving IPv6 multicast data traffic using MLD Query messages. Listeners send MLD Report and MLD Done messages. MLD Reports contain multicast addresses and potentially source addresses that interests the listeners. A MLD agent keeps track of these multicast addresses and source addresses for its attached links on which MLD is enabled. Since only one router needs to send queries, a querier election takes place to select...
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UDF flex hashing improvements

This feature enables user to configure the list of bytes from the packet which can be used for Lag/Ecmp hashing in the EOS. This feature will program the hardware to hash the packets based on offset information. This hashing behavior is applied for the user configured packet types on all the ports. There is no interface level configuration for the flex hashing. The user can select the packet types based on the Ethernet-type and/or IP-protocol number. The user can reach up to 64 bytes from the starting of the packet to select the fields for hashing. Supported Platforms: 7050-series (excluding...
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VLAN Policy Configuration CLI

This feature is available in the VLAN configuration mode. When a switch receives a packet with unknown destination MAC address on a VLAN, L2 miss happens. The current behavior for L2 miss packets is to flood the packet on all ports of the VLAN. Sometimes the customers want to drop or log the L2 miss packets instead of flooding them on the VLAN. VLAN Policy Configuration CLI allows customers to configure how the L2 miss packets should be treated for each VLAN. There are three options available: Flood the L2 miss packets on the VLAN (default behavior) Drop the L2...
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