• Tag : EOS-4.18.0F

 
 

Directed Broadcast

Directed broadcast is method of transfer to send a packet to recipients in a target subnet. This is done by sending a directed broadcast packet as a standard unicast packet until it reaches a switch connected to the target subnet. Then, the packet is broadcast to reach all recipients in the target subnet. Directed broadcast packets are designated by having a IP destination address that is the broadcast address for the target subnet. When a directed broadcast is received, if the receiving switch is not connected to the target subnet, then packet is forwarded as a normal unicast packet. If...
Continue reading →

ISIS ignore attach bit

The default behavior of a level-1 router running IS-IS is to install a default route to a level-1-2 router present in a different area after it finds the attach-bit set in the incoming LSPs from a level-1-2 router. Sometimes this behavior may not be desired and the user might wish for IS-IS on level-1 router to ignore the attach-bit in the incoming LSPs and skip installing a default route to the level-1-2 router. Platform compatibility ISIS ignore attach bit feature is supported on all platforms. Configuration The following command is available under the config-router-isis-af mode. Arista(config)#router isis <Isis Process ID>...
Continue reading →

BGP Fallback AS

BGP Fallback AS offers the ability for BGP peering relationships be established with either the local-as or the router-as. This assists in deployments where the peer AS is expected to change as it avoids the need for concurrent configuration updates. For example, if a service provider is updating their ASN from <old-ASN> to <new-ASN>, peers must make corresponding changes to their eBGP configuration to accept the new value. This will involve configuration updates on both sides of the peering relationship. If the updates are not co-ordinated, connectivity may be lost. With fallback AS, the service provider can configure their BGP...
Continue reading →

OSPF Max LSA Retransmission Threshold

The OSPF Max LSA Retransmission Threshold feature adds a configurable limit to the number of LSA update retransmissions. OSPF sends LSA updates to its OSPF neighbors in a Link State Update packet. The neighbor acknowledges that it received and accepted the LSA update by sending a LSA Acknowledgment in a Link State Acknowledgement packet. If a LSA acknowledgment is not received in the configured retransmit interval from a neighbor, OSPF retransmits the LSA update to that neighbor. Retransmissions will continue until an acknowledgement is received or the maximum retransmission limit is reached. When the limit is reached for a neighbor,...
Continue reading →

OSPF and OSPFv3 Non Stop Forwarding

Introduction The OSPF Non Stop Forwarding (NSF) feature adds support for Graceful OSPF Restart (IETF RFC 3623) and Graceful OSPFv3 Restart (IETF RFC 5187) . When OSPF Graceful Restart (GR) is configured, a Smart System Upgrade (SSU), redundancy switchover from active to standby supervisor, or a restart of the OSPF software should be hitless. Neighboring routers continue to forward traffic to the restarting router, and traffic forwarding through the restarting router continues without loss. If GR is successful, router downtime should be completely transparent to network applications. NSF allows the router to retain its hardware routing tables (Forwarding Information Base/FIB)...
Continue reading →

Storm Control: Rate limiting unknown unicast packets

  Introduction A traffic storm is a flood of packets entering a network, resulting in excessive traffic and degraded performance. Storm control prevents network disruptions by limiting traffic beyond specified thresholds on individual physical LAN interfaces. Storm control monitors inbound traffic levels over one-second intervals and compares the traffic level with a specified benchmark. The storm-control command configures and enables storm control on the configuration mode physical interface. Unknown unicast storm control is another mode added to the existing storm control command. This mode provides the capability to rate limit unknown unicast traffic to a user configurable value in pps...
Continue reading →

DirectFlow

DirectFlow runs alongside the existing layer 2/3 forwarding plane, enabling a network architecture that incorporates new capabilities, such as TAP aggregation and custom traffic engineering, alongside traditional forwarding models. DirectFlow allows users to define flows that consist of match conditions and actions to perform that are a superset of the OpenFlow 1.0 specification. DirectFlow does not require a controller or any third party integration as flows can be installed via the CLI. Platform compatibility DCS-7010T DCS-7010T-DC DCS-7050S DCS-7050T-36 DCS-7050T-52 DCS-7050T-64 DCS-7050TX DCS-7050SX DCS-7050QX DCS-7260QX-64 DCS-7060CX-32S DCS-7060CX2-32S DCS-7250QX DCS-7260CX DCS-7300X DCS-7320X Configuration Directflow supports flow configuration at different stages of the...
Continue reading →

WRED Support

WRED ( Weighted Random Early Detection ) is one of the congestion management techniques. It works at queue level to drop packets randomly after crossing given queue threshold even before queue is full. Without WRED, all newly arriving packets get tail dropped once the queue is full, which creates TCP global synchronization issue. WRED helps to avoid TCP global synchronization. Platform compatibility DCS-7050X DCS-7300X DCS-7250X Configuration This is configured at interface’s tx-queue level. The drop profile is defined by minimum-threshold, maximum-threshold and drop-probability. The units for thresholds can be given in segments ( 1 segment is equivalent to 208 bytes on T2...
Continue reading →

Aggregate Storm Control per Traffic Class

Introduction Aggregate storm-control with traffic-class option provides the capability to rate limit BUM( Broadcast, Unknown-unicast, Multicast ) traffic to user configurable value in pps( minimum value can go to 1 pps ) per traffic-class across all ports in the system. Platform compatibility DCS-7050QX DCS-7050SX DCS-7050TX DCS-7260QX-64 DCS-7060CX-32S Configuration CLI command to configure aggregate storm-control per traffic-class is Arista(config)#[no] storm-control bum aggregate traffic-class <tc> level pps <rate> ‘bum’ means BUM ( broadcast, unknown-unicast, multicast ) traffic. ‘aggregate’ means all ports. This will create a shared policer instance and attach entries corresponding to traffic-class to it. Sample configuration Arista(config)#storm-control bum aggregate traffic-class...
Continue reading →

Per port Per VLAN Qos range

Classification of traffic for QoS policies on a per-port-per-vlan basis is already supported and corresponding information can be found here – http://eos.arista.com/eos-4-17-0f-toi/per-port-per-vlan-qos/. ‘match vlan’ configuration under a class-map helps in programming that configuration. This enhancement to the ‘match vlan’ is to allow configuration for multiple vlans as a range (single range or comma-separated multiple ranges) instead of just vlan and a mask. This feature only works with QoS-based class-maps. Platform compatibility DCS-7010T DCS-7050X DCS-7250X DCS-7260X DCS-7280E, DCS-7280R DCS-7300X DCS-7320X DCS-7500E, DCS-7500R Configuration Please refer to EOS configuration guide to configure ACL policing QoS and per-port-per-VLAN. Once created, policy-maps can be...
Continue reading →

Policy maps under QoS Profiles

QoS profiles have been applicable on fabric and front panel ports across all platforms from EOS 4.17.0F release onwards with support for all interface level QoS configurations. Support for application of a policy-map under QoS profile has now been added in EOS 4.18.0F. The same policy-map can be applied through QoS profile on one interface and directly attached on another. If two policy-maps are applied on an interface through directly and QoS profile, the one applied directly is given more priority and used. Configuration The command to configure a policy-map under qos profile is – Arista(config)#qos profile <qos-profile name> Arista(config-qos-profile-name)#service-policy...
Continue reading →

Explicit Congestion Notification (ECN) Counters

This enhancement is to display the number of packets that were ECN (Explicit Congestion Notification) marked by the switch. The counter value does not include the incoming packets that were already marked. The existing show platform trident counters will now display this counter as an additional item. Platform compatibility DCS-7060X series DCS-7260X series DCS-7320X series Configuration These counters are enabled by default and no configuration is required. Show Commands The command show platform trident counters will display the ECN marked packets value. Arista#show platform trident counters interface ethernet 8 … Ethernet8 TX – ECN marked packets 124 …

SMPTE and AES PTP Profile Support

The SMPTE ST 2059-2:2015 and AES67-2013 standards define PTP profiles specifically developed for synchronization of audio and video streams being transported over an IP network. Each of these PTP profiles leverage the existing IEEE-1588 standards and vendor implementations while defining message rates and management messages unique to the requirements of rapid synchronization of end points for media streams. In this release, we have added support for both PTP profiles on all Arista platforms currently supporting PTP. The following additions were made. Expanded Maximum PTP Message Rates Both SMPTE ST 2059-2:2015 and AES67-2013 define faster message rates than what was previously...
Continue reading →

MLAG Unicast Convergence

Feature Update: Please note that this feature has been updated and enhanced in EOS-4.24.1F On an MLAG chassis we sync the MAC addresses learnt on individual peers and make sure we use the appropriate interface to map the MAC addresses. In case of unexpected events like reloading of one of the peers in the MLAG chassis or flapping of one or more MLAG interfaces, we may observe some loss of traffic. If an MLAG flaps on one peer, then we may have to remap the MAC addresses learned, such that the reachability is via the other peer in the MLAG...
Continue reading →

PFC Global Knob

PFC ( Priority-based Flow Control ) is a flow control mechanism used in RDMA environments. PFC provides a link-level flow control mechanism that can be controlled independently for each Class of Service ( Cos ). The PFC global [on|off] knob is a CLI command to enable or disable PFC functionality on the switch globally. This command will apply to all interfaces, including fabric interfaces in the case of multi-chip devices. This feature is supported from EOS-4.18.0F onwards. Functionality PFC configuration will now be honored only when the PFC global knob is enabled. If the PFC global knob is disabled, the...
Continue reading →

Config Session Commit Timer

The Commit Timer mechanism provides a way to automatically rollback changes done by a config session, unless confirmed within a certain interval. This is especially useful when the user commits configuration changes that can potentially cause a network disruption. After issuing a commit timer operation, the user is required to a second commit of that session, to confirm that the changes need to be persisted. If due to any reason (such as network disruption), the user is not able to issue the second commit, the system will automatically rollback to the previous state at the end of the timer. Platform...
Continue reading →

Usage of RADIUS VSAs in Role-Based Access Control

Role-based access control (RBAC) is an approach to regulating access to network resources based on the roles of individual users. Each user has one or more roles. Each role has its own rules which indicate the allowed and denied commands under specified mode. Commands authorization of a user is performed based on these rules. RADIUS RBAC allows users to configure roles and rules by using Vender-Specific Attributes (VSAs) on the RADIUS server side, which is a much more scalable solution than local RBAC. Configurations can be set and modified on the server side once and applied to all switches who...
Continue reading →

Hardware load-balancing for ingress/egress and fabric/egress replication

In ingress/egress and fabric/egress replication mode, on DCS-7280E, DCS-7280R, DCS-7500E and DCS-7500R, Broadcast, Unknown Unicast and Multicast (BUM) traffic is load balanced over LAG members on a per-replication group basis. Distribution of BUM traffic and multicast groups over LAG member ports is decided by software and the hardware is configured accordingly. This would result in following shortcomings: As each replication group is associated with a specific LAG member port, the member port may carry more traffic than other members of the LAG (BUG177895). When a LAG member goes down, the replication groups carried by it are redistributed to other LAG...
Continue reading →

BFD RFC7130

This document describes about RFC7130 on EOS. RFC7130 defines a mechanism to run BFD protocol on LAG with an independent asynchronous BFD session on every LAG member link. With the support of RFC7130, any broken or erroneous member link of the LAG is cleared out with up BFD session flap on the member link. Configuration The following configuration example enables this feature under a routed or switchport port-channel. Arista(config-if-po1)#bfd per-link rfc-7130 Arista(config-if-po1)#[ no | default ] bfd neighbor 10.0.0.4 This enables or disables BFD RFC7130 on that port-channel. It is disabled by default. Please note that both the above configurations...
Continue reading →

Follow

Get every new post on this blog delivered to your Inbox.

Join other followers: