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Understanding Table Sizes on the 7050QX-32

A common question asked about Arista switches is “how many routes can they handle”, and unfortunately, this is never an easy question to answer. Dedicated switch ASIC hardware is required to program each route so that when a packet arrives with a certain destination address, the switch can look up the destination and route the packet to the correct interface at line-rate across all the ports. The part that makes it hard is that there is practically never a 1:1 mapping between hardware resources on a switch and the number of routes that can be programmed into them, and under...
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Curl’ing with EOS and third party devices

Perhaps you’re aware that EOS is based on Linux, which comes with many powerful & useful built-in utilities. I recently wrote an EOS Central article on sed. Even if you are not a pure networking person (perhaps you’re a server person), many of the familiar Linux tools you have used in your past exist on EOS natively today. One of my customers recently shared an experience with me that made me smile because they had now started to embrace the Linux underpinnings & power of EOS after running into a configuration challenge with a 3rd party (television) broadcast IP/SDI gateway...
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A simple GNU sed example on EOS

Hopefully by now you are aware that Arista EOS (Extensible Operating System), which is the operating system that runs on Arista switches, is based on Linux. From the CLI you can drop to the Bash shell by just typing bash. Given that EOS is based on Linux you already have access to many of the helpful utilities seen in many Linux distributions. Let’s pretend that you have a configuration file that was copied over from another very similar configuration and that the only thing that needs to change is every occurrence of IP addresses that look like 10.0.x.y. This is...
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CloudVision Event Guide

ContentsOverviewCVP EventsBUGALERTS_CVE_EXPOSEDCONNECTIVITY_MONITOR_ANOMALYLOW_DEVICE_DISK_SPACEHIGH_CONN_MONITOR_PKT_LOSSHIGH_CPU_LOAD_AVGHIGH_INTF_FCS_ERRSHIGH_INTF_IN_ERRSHIGH_INTF_OUT_DISCARDSHIGH_INTF_OUT_ERRSHIGH_PTP_OFFSET_FROM_MASTERHIGH_ROUTING_TABLE_SIZEHIGH_STREAMING_LATENCYSYSLOG: DeqDelete Overview This article identifies some of the common CloudVision Events and provides information regarding the events themselves or references to troubleshoot the underlying cause of the events. CVP Events BUGALERTS_CVE_EXPOSED Explanation: CVP detected a potential CVE on the switches. For more information, please visit https://www.arista.com/en/support/advisories-notices. CONNECTIVITY_MONITOR_ANOMALY Explanation: The cloudtracer latency anomaly event monitors the latency metric between devices and configured hosts. CVP detected a deviation in these metrics from the historical bounds. For more information, please visit https://eos.arista.com/toi/cvp-2020-1-0/events/#CloudTracer_Latency_Anomaly_Events. LOW_DEVICE_DISK_SPACE Explanation: CVP detected that the filesystem space on a device is below the set threshold. To debug  possible...
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How to Collect Arista AP/Sensor Debug Logs

ContentsIntroductionPrerequisitesSolutionCollecting Debug Logs via CVWCollecting Debug Logs via WMCollecting Debug Logs via the AP/Sensor CLI Introduction This document provides the steps to fetch debug logs from Arista devices. These logs are required by the Arista WiFi TAC team at the time of troubleshooting.You can download and save a debug log for future reference. The debug logs are available in .tgz format. There are multiple methods to fetch AP/Sensor debug logs: Via the UI of CloudVision WiFi (CVW) or Wireless Manager (WM). This requires the AP/Sensor and WM to be on software version 7.3 or above. Via the config CLI of...
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How to Configure an SSID on Arista APs using Wireless Manager

ContentsIntroductionPrerequisitesSolutionSetting up Location and Device PresenceSetting up an SSID ProfileSetting up the Device TemplateOther Important Configuration Introduction This document focuses on the basic prerequisites and minimum configuration required for configuring an Arista device as an AP.  Prerequisites Administrative access to the Wireless Manager UI. Access Point should be connected to the network and also active on the Wireless Manger. If you do not see the Access Point active on the server, please refer to Troubleshoot AP Server connectivity. Solution The Arista AP does not have a UI of its own, so it must be configured via Wireless Manager. There are...
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Troubleshooting Egress Queue drops on 7280/7500 devices

ContentsAggregate VoQ drops on 7280/7500 devicesEgress Queue drops on 7280/7500 devicesSolutionConfigurationValidationAdditional References Aggregate VoQ drops on 7280/7500 devices On 7280/7500 devices, the platform architecture uses Virtual Output Queuing (VoQ) between the ingress and egress chips to forward known unicast traffic. Whenever a packet is to be transmitted, the ingress chip requests for credit from the egress. Once the credits are issued/granted, the packet is dequeued to the egress chip. While the packets are awaiting the credit, they are enqueued on the ingress chip buffers, in the Virtual Output Queue (VoQ) for the corresponding egress port. Accordingly, in the output of...
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Troubleshooting RADIUS Authentication/Authorization Issues

ContentsIntroductionPrerequisitesFeature DescriptionSolutionTroubleshootingBasic ChecksCommon Configuration Errors Common Error Codes and Possible Solutions Introduction Arista Access Points offer several authentication methods for client connectivity, including the use of external authentication servers to support WPA2-Enterprise. This article outlines Dashboard configuration to use a RADIUS server for WPA2-Enterprise authentication, RADIUS server requirements and basic troubleshooting of RADIUS authentication. Prerequisites All Arista APs must be added as RADIUS clients on the RADIUS server. It is recommended that a static IP assignment or a DHCP fixed IP assignment should be used on the APs. Corresponding user authentication policies must be in place on the RADIUS server....
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Dynamic VLAN Support Using RADIUS and Google Integration

ContentsIntroductionSolutionRADIUS Based AssignmentGoogle OU Based Assignment Introduction Dynamic VLAN assignment helps you to quickly on-board a new device by allowing it to connect to a single SSID irrespective of the VLAN it has access to. Users can get access to their respective VLANs by connecting to a single corporate SSID. With dynamic VLAN assignment RADIUS server maps these users to their respective VLANs at the back end. The APs need to be connected to a trunk port that carries all the VLANs. There are two methods to assign Dynamic VLANs: RADIUS Google OU Solution RADIUS Based Assignment To achieve this,...
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Troubleshooting Metawatch

ContentsWorking of Metawatch Troubleshooting Metawatch Issues related to the Time source and its sync Issues related to the Packet drops , which can cause the gaps in the multicast flow or other flows which are getting timestamped Some packets are missing sporadically and we were doubtful whether Metawatch was dropping those frames  Working of Metawatch  Metawatch is an application (app) that runs on the Arista 7130 devices to perform highly accurate timestamping and aggregation across a large number of ports in a single device. The aggregated output is suited for feeding to an analytics application server or backend. The layer 1 functionality in Arista...
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How to Troubleshoot Low Throughput Issues on a Wireless Network

ContentsIntroductionPrerequisitesSolutionOptimize the Radio SettingsCheck Bandwidth and QoS SettingsTests to Validate the ThroughputEnvironment Checklist Introduction Data Rate is not the same as the actual Throughput achieved for a wireless network. The term Data Rate usually specifies the theoretical bit transfer rate of a particular implementation of Radio Frequency (RF) transmission. Whereas, Throughput is the actual amount of data per second that can be pushed across the link. Some spreading technologies are more effective than others, so the throughput will vary. 802.11 RF medium is a shared medium, meaning that in any discussion about throughput, it should be thought of as aggregate...
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Operation of the Route-Map ‘continue’ feature with CLI outputs

ContentsSupported PlatformsBackground of the default operation of a route-mapOverview of the route-map  continue command and its effectsBenefits of the route-map  continue featureApplications of the route-map continue feature in different scenarios and their effectsNetwork DiagramScenario 1a) Child Seq sets different attribute not set by Parent Seq (Inbound Policy Demo)Scenario 1b) Child Seq sets  different attribute not set by Parent Seq (Outbound Policy Demo)Scenario 2) Child Seq overrides attribute set by Parent SeqScenario 3)   Where the Child Seq too has a continue, diverting to another Child Seq Scenario 4a) When Child Seq that denies route permitted by Parent, is not followed by...
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How to Enable Automatic Packet Capture

ContentsIntroductionUse casePrerequisitesSolutionValidate/VerifyCaveats Introduction CloudVision WiFi can automatically capture packet traces when an AP detects a connectivity failure. The captured packet traces can be accessed and downloaded from the CloudVision WiFi GUI under Connection Logs. Use case This feature is useful for troubleshooting random client connectivity issues that last for a short duration and hence make it difficult for the administrator to capture the trace. For example incorrect password, DHCP and DNS issues Prerequisites Administrator or higher access to CloudVision WiFi/Wireless Manager. Solution On CloudVision WiFi, navigate to Troubleshoot > Packet trace > Auto Packet Trace Click on Auto Packet Trace...
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How to Enable Application Firewall on Arista Access Points

ContentsIntroductionPrerequisitesSolutionEnable Application Firewall via CVWEnable Application Firewall via WMValidate/VerifyTroubleshooting Introduction Arista Access Points include an Application Firewall feature, which allows you to define firewall rules at application level/Layer 7. This feature can be useful in corporate environments where the requirement is to either allow or block certain applications. The applications that the Arista APs are able to recognize can be broadly classified into the following categories. Messaging Proxy File Transfer Networking Web Services Remote Access VPN and Tunneling Database Network Monitoring Collaboration Games Streaming Media Streaming Media- Messaging Mail Social Networking Prerequisites Administrative access to CloudVision WiFi (CVW) / Wireless...
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Onboarding a switch in CVP

ContentsDescriptionPlatform compatibilityConfigurationShow CommandsHow to onboard a switch using CVP GUI?What goes on during the onboarding process? Troubleshooting onboarding/registration failures1. Switch unreachable via eAPI 2. Unauthorized user3. EOF4. No route to host5. Unable to reach CVP from the device in any VRF6. “Error received from device” and “Timed out waiting for response from device” Description This article will talk about how to onboard a switch in CVP 2019.1.x/2020.1.x and will deep-dive into the process involved during the registration process. In addition, we will also include the troubleshooting steps that can be taken in case the registration process fails.  Platform compatibility This feature...
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Launching CloudEOS in Azure with Terraform

ContentsLaunching CloudEOS in Azure with TerraformIntroductionDiagramPrerequisitesProvider DefinitionResource Group DefinitionVNet DefinitionSubnet DefinitionSecurity GroupsSecurity Group DefinitionSecurity Group AssociationPublic IPNetwork Interface DefinitionRoute Table and RoutesDefine Route Tables and RoutesAssociate Subnets to the Route TablesCloudEOS DefinitionCloudEOS InstanceSample Bootstrap Configuration for the CloudEOS InstanceHostSample Bootstrap Configuration for the HostOutputRunning the Terraform ScriptAdditional Arista Terraform Example Material Launching CloudEOS in Azure with Terraform Introduction Enterprise cloud organizations are orchestrating environments in the cloud.  This can be done with cloud native tools such as AWS CloudFormation or Azure Resource Manager Templates.  However, Terraform is winning enterprise mindshare as a cross-cloud orchestration system, and this post is an...
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Launching CloudEOS in AWS with Terraform

ContentsLaunching CloudEOS in AWS with TerraformIntroductionDiagramPrerequisitesProvider DefinitionVPC DefinitionSubnet DefinitionInternet GatewaySecurity Group DefinitionNetwork Interface DefinitionRoute Table and RoutesDefine the Route TableDefine the RoutesAssociate Subnets to the Route TablesEIPCloudEOS DefinitionCloudEOS InstanceSample Bootstrap Configuration for the CloudEOS InstanceHostSample Bootstrap Configuration for the HostOutputRunning the Terraform ScriptAdditional Arista Terraform Example Material Launching CloudEOS in AWS with Terraform Introduction Enterprise cloud organizations are orchestrating environments in the cloud.  This can be done with cloud native tools such as AWS CloudFormation or Azure Resource Manager Templates.  However, Terraform is winning enterprise mindshare as a cross-cloud orchestration system, and this post is an example of a simple...
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Monitoring Link Quality Using Forward Error Correction (FEC) Data on Arista Switches

ContentsIntroductionForward Error CorrectionReed-Solomon FECTransmitting with RS-FECReceiving with RS-FECWhen Correction FailsMonitoring RS-FECShow Interfaces Phy DetailPre-FEC BER vs SERFEC Correction HistogramsFirecode FEC400G Histogram ExamplesSummaryReferences Introduction When forward error correction is enabled, it provides a set of statistics which can be used to monitor the health of the link at layer 1.  By comparing trends over time it may be possible to predict which links may experience service impacting error rates allowing action to be taken before these events. This document will describe these statistics and how to monitor them on an Arista switch running EOS.   Forward Error Correction Forward error correction (FEC)...
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How to Configure Alerts in CloudVision WiFi

ContentsIntroductionPrerequisitesSolution Introduction This article will give you a brief idea about configuring Alerts in CloudVision WiFi. An alert provides a means to notify network admins of network events that need their attention. Alerts can be configured at individual locations in the hierarchy. If an alert is configured at the parent location, the same alert configuration will be inherited by the child location unless the administrator creates a different alert configuration at the child location. Prerequisites Administrator access to Wireless Manager and CloudVision WiFi Wireless Manager should be running version 8.6.0 or higher and CloudVision WiFi should be on version 2.3...
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How to Install CloudVision WiFi plugin for On-Premises Wireless Manager

ContentsIntroductionPrerequisitesSolutionValidate/VerifyCaveats Introduction CloudVision WiFi is extremely useful in troubleshooting WiFi client connectivity or network related issues. It is available as a service to Arista Cognitive WiFi Cloud customers, and can also be configured as a plugin for Wireless Manager in an On-Premises environment. Prerequisites Wireless Manager (WM) must be upgraded to version 8.5.1 or above Administrator must download CloudVision WiFi (CVW) plugin file from the WiFi Customer Portal. Release Notes will include information on WM and CVW compatibility. CVW plugin bundle must be hosted at a location from where it can be downloaded on WM, using one of HTTP, FTP,...
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