Tag :: EOS 4.33.1F

The software for Syslog, NTP and SNMP used in EOS resolves hostnames at service start-up. It’s possible that during service operation, the configured host becomes unavailable and the configuration needs to be set to a different host to continue the service. The problem is that such change requires manual restart of the service. Even if the hostname doesn’t change and only the underlying address is updated at the DNS server, the administrator has to manually reset service configuration.

The rate watermark counters feature allows for the capturing of microbursts within a configured interval based on the fast interface counters. The rate watermark counters feature is built on top of the high frequency fast poll counters which allows for increased visibility of microbursts that may happen within a short time window.

Equal Cost Multi-path (ECMP) provides the ability to load-share traffic across multiple next-hops. When a next-hop fails or is deleted all flows are affected. This is due to the nature of the load-balancing algorithm which re-calculates a new hash for the flows based on the remaining active next-hops.

Routing control functions (RCF) is a language that can be used to express route filtering and attribute modification logic in a powerful and programmatic fashion.

This document describes the support for performing SSH authentication with X.509 certificates. Authentication to SSH can be completed using a number of different methods. Public key, password and keyboard interactive are supported in EOS. Certificate login is a type of public key authentication in which the public key does not have to be stored on the server. Instead certificates belonging to trusted certificate authorities (CAs) are installed.

Subinterfaces are logical L3 interfaces that enable the division of a single Ethernet or Port-channel interface into multiple logical L3 interfaces based on the incoming 802.1q tag.  They are commonly used in the L2/L3 boundary.  They can also be used in the context of VRF-lite, by configuring each subinterface in a different VRF.

This feature extends the existing UDP payload hashing support to allow an alternative set of bytes to be used in the calculation of the LAG and ECMP hash if an 16 bit field of the payload matches a provided pattern.

This feature adds support for CPU traffic policy capable of matching and acting on IP traffic which would otherwise

This feature adds support for “Dynamic Load Balancing (DLB)” on Equal Cost Multi Path (ECMP) groups.
It is intended to help overcome the potential shortcomings of traditional hash-based load balancing by considering the traffic load of members of ECMP groups. DLB considers the state of the port while assigning egress ports to packets, resulting in a more even flow. The state of each port member is determined by measuring the amount of data transmitted from a given port and total number of packets enqueued to a given port.

This feature provides a CLI command showing the list of mac addresses that could not be learned due to hash collision in the hardware table. A hash collision occurs when two or more distinct pieces of data map to the same entry ( or slot ) in the hardware table. It can happen when the hash function used to calculate the index for a given mac address results in the already occupied index, resulting in the failure of inserting the later mac address to the hardware table.

Private VLAN is a feature that segregates a regular VLAN broadcast domain while maintaining all ports in the same IP subnet. There are three types of VLAN within a private VLAN

A remark is a user specified comment that is written within an IP prefix-list. Remarks allow documentation to be added directly into the configuration of an IP prefix-list. Both IPv4 and IPv6 prefix-lists are supported.

There are two types of reload on a switch running EOS, normal reload and Smart System Upgrade (SSU). Scheduled normal reload is supported via ‘reload in’ command, to perform a normal reload after a specified delay. It asks for saving unsaved configuration changes and confirmation in order to schedule the reload. Scheduled SSU is supported via ‘reload fast-boot in’ command. However, after scheduling an SSU reload, if there are unsaved configuration changes, or saved configuration changes which block an SSU reload, the scheduled reload will be aborted at scheduled time.

This feature introduces the support for Traffic Policy on VLANs. Traffic Policy allows the user to configure rules to match on certain packets through the packet processing pipeline. The user can also place actions to match packets.

This document describes the support for user-defined fields (UDF) ACL rules in egress mac/IPv4/IPv6 access lists. This feature is an extension of egress ACL to allow increased flexibility of the match criteria by using user-defined fields which will help customers control traffic based on other parts of the packet header and payload that is not supported by the other key-fields.

This feature allows the export of IP FIB (Forwarding Information Base) through the OpenConfig AFT YANG models.

SwitchApp is an FPGA-based feature available on Arista’s 7130LB-Series and 7132LB-Series platforms. It performs ultra low latency Ethernet packet switching. Its packet switching feature set, port count, and port to port latency are a function of the selected SwitchApp profile. Detailed latency measurements are available in the userguide on the Arista Support site.

Topology Independent Fast Reroute, or TI-LFA, uses OSPF SR to build loop-free alternate paths along the post-convergence path. These loop-free alternates provide fast convergence.

EOS 4.15.0F added support for a CLI knob to determine whether the L3 forwarding agent (responsible for programming FECs and routes into hardware) would react to BFD status events for an interface to update next-hop programming for FECs programmed in hardware. This required two events, one for the BFD session to transition to an “Up” status and a subsequent transition to a “Down” status. This is identical to how various protocols in EOS (i.e. BGP, IS-IS) leverage BFD for faster down detection, and is useful to allow the L3 forwarding agent to preemptively remove next hops that would later be deprogrammed due to protocol session status state.

The Tap Aggregation Traffic Steering feature provides support for filtering data streams received on tap ports and directing flows to tool ports based on user-configurable match rules, using either class maps and policy maps or traffic policies.

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. In certain cases, there may be a preference to drop or log L2 miss packets instead of flooding them across the VLAN.

This feature allows an operator to configure a centralized routing topology with an IPv6 VXLAN underlay. This is useful for customers who want to use an anycast (VARP) gateway for routing over an IPv6 control plane. VARP allows multiple switches to simultaneously route packets from a common IP address in an active-active router configuration. Each switch is configured with the virtual IP address and a common virtual MAC address.