Category : Tech Tips

Objective The objective of this article is to understand how EVPN OISM (Optimised Inter Subnet Multicast) operates in certain scenarios/designs and understanding the logical flow. This article is best suited if you have already read the below TOI and have some trouble understanding how it would work in real world: https://eos.arista.com/eos-4-25-1f/multicast-evpn-irb/ Scenarios Scenario 1 Topology In above topology, host Sender multicast traffic is in Vlan 10 connected to VTEP-1 and Receiver is Vlan 20, connected to VTEP-2. Please ignore VTEP-3 for now. Vxlan Configuration On both VTEP-1 and VTEP-2 (showing output only for VTEP-1): BGP Configuration VTEP-1 BGP Underlay neighbour...
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Introduction When install a 7500N chassis in a rack that provides adequate clearance for removing front and rear components. Arista 7500N Quick Start Guide states the Clearance requirements and footprint for switches.   7500R/R2 Line Card Clearance Since Quick Start Guide mentioned clearance is only for front and rear side, we added more clearance information here in the left and right space for 7500R/R2 Line card as below: Max width (when ejector open and pull out line card) 7500R/R2   The above 2 diagrams show the clearance of left and right in a rack  which is for linecard eject handle...
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Introduction Starting with EOS 4.22.0F, the show vxlan config-sanity command can be used to highlight various common errors in a VxLAN setup. This command is platform-independent. CLI Details switch# show vxlan config-sanity [ options ] VXLAN Config Sanity CLI has the following options. # show vxlan config-sanity (displays details for only FAIL and WARN checks) # show vxlan config-sanity brief (displays a brief output for FAIL and WARN checks) # show vxlan config-sanity detail (displays details for all checks) RESULT column may have one of these three entries:  The status “OK”  indicates a good configuration Status “FAIL” indicates a misconfiguration...
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If you’ve tried implementing VXLAN on Trident VTEPs with a Layer-2 uplink to remote-vteps, you may have noticed that sometimes packets can’t be successfully forwarded across the VXLAN fabric, or perhaps the latency observed is higher than what’s expected. Alternatively, maybe you never noticed the above symptoms and are here instead because you noticed the following log in your switch: STRATA-6-VXLAN_PORT_TO_NEXTHOP_OVERFLOW. These are the most common observations made when a Trident switch has hit the following limitation, 113722, found in EOS Release Notes: Limitations and Restrictions in 4.26.1F 7300X3, 7320X, 7368, CCS-720XP, CCS-750, DCS-7010, DCS-7050X, DCS-7050X2, DCS-7050X3, DCS-7060X, DCS-7060X2, DCS-7060X4,...
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Overview Multicast is a means of sending data from one source to many receivers.  To understand what one to many looks like no further than a TV streaming service and or a paging system which calls only certain phones.  Unlike broadcast which multicast may act like depending on the design, typically multicast packets are not meant for the whole network but to a set of end points for a specific group.  Sending to a group is achieved by sending data to a multicast IP whose range is from 224.0.0.1 to 239.255.255.255.   For data to flow from its publisher or source,...
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Introduction Quality of Service (QoS) is the ability to provide different priorities to different applications, users, or data flows, or to guarantee a certain level of performance to a data flow. QoS processes apply to traffic that flows through Ethernet ports and control planes. These processes can modify data fields (Class of Service (CoS) or Differentiated Services Code Point (DSCP)) or assign data streams to traffic classes for prioritised handling. In this document we will be implementing a basic enterprise QoS model. Consider the following topology for the following examples:   What do we want to achieve In this example,...
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What is DNS? The Domain Name Server (DNS) maps FQDN labels to IP addresses and provides addresses for network devices. How to install it on EOS switch? EOS has a pre-installed DNSmasq service that can be used as a lightweight DNS server. The switch can be used in the recursive mode to take the local and external requests and forward them to an upstream DNS server.  Each network requires at least one server to resolve addresses. The configuration file can list a maximum of three server addresses. Configuration Step 1: In EOS CLI configure a name-server: ip name-server vrf default...
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Arista switches have the capability to break out QSFP and OSFP interfaces to multiple lanes of smaller speeds. This can be very useful for high density deployments that require a minimal RU footprint by maximizing the ports available on various Arista platforms. With QSFP interfaces, whether it be for 40G or 100G speeds, these are implemented as 4 lanes that can be independently controlled & configured. With 40G interfaces, these interfaces can operate in 4x10G speeds and for 100G interfaces can operate in 4x25G or 2x50G speeds .        As an example, with the Arista 7280CR2A-30 switch which comes with 30...
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Objective The goal of this document is to guide you through the setup of CloudEOS in AWS and/or Azure using CloudVision as-a-Service and the Terraform CloudEOS examples in the Arista GitHub repository. Obtain a CloudVision as-a-Service Account Work with an Arista account team member to procure a CloudVision as-a-Service account. Download and Install Terraform From www.terraform.io, download Terraform 13 or above.  It is best to place the terraform binary file in the PATH of your workstation for ease of use. Download and Install Cloud Provider CLI For AWS Cloud Deployment For an AWS demonstration environment, download and install AWS CLI...
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