{"id":436,"date":"2025-03-28T20:34:21","date_gmt":"2025-03-28T15:04:21","guid":{"rendered":"http:\/\/ipwithease.com\/?p=436"},"modified":"2025-04-04T18:18:30","modified_gmt":"2025-04-04T12:48:30","slug":"vpc-vs-vss","status":"publish","type":"post","link":"https:\/\/ipwithease.com\/vpc-vs-vss\/","title":{"rendered":"Cisco vPC vs VSS"},"content":{"rendered":"<div id=\"ipwit-2947202946\" class=\"ipwit-before-content ipwit-entity-placement\" style=\"width: 728px;\"><div class=\"ipwit-adlabel\">Google ADs<\/div><div style=\"height: 90px;\"><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-1375203873676133\" crossorigin=\"anonymous\"><\/script><ins class=\"adsbygoogle\" style=\"display:inline-block;width:728px;height:90px;\" \ndata-ad-client=\"ca-pub-1375203873676133\" \ndata-ad-slot=\"9359532231\"><\/ins> \n<script> \n(adsbygoogle = window.adsbygoogle || []).push({}); \n<\/script>\n<\/div><\/div>\n<div class=\"wp-block-rank-math-toc-block has-background\" style=\"background-color:#e9faf9\" id=\"rank-math-toc\"><h2>Table of Contents<\/h2><nav><ul><li><a href=\"#what-is-v-pc-virtual-port-channel\">What is vPC (Virtual PortChannel)<\/a><ul><li><a href=\"#pros\">Pros<\/a><\/li><li><a href=\"#cons\">Cons<\/a><\/li><\/ul><\/li><li><a href=\"#what-is-vss-virtual-switching-system\">What is VSS (Virtual Switching System)<\/a><ul><li><a href=\"#pros-1\">PROS<\/a><\/li><li><a href=\"#cons-2\">CONS<\/a><\/li><\/ul><\/li><li><a href=\"#comparison-table-v-pc-vs-vss\">Comparison: vPC vs VSS<\/a><ul><li><a href=\"#similarities\">Similarities<\/a><\/li><li><a href=\"#differences\">Differences<\/a><\/li><\/ul><\/li><li><a href=\"#which-one-should-you-choose\">Which One Should You Choose?<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n<p>Both VPC and VSS are used basically to support <a href=\"https:\/\/community.cisco.com\/t5\/data-center-switches\/difference-beetween-multichassis-etherchannel-mec-and-vpc\/td-p\/3888771\" target=\"_blank\" rel=\"noreferrer noopener\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">multi-chassis ether-channel<\/mark><\/a> that means we can create a port-channel whose one end is device A, however, another end is physically connected to 2 different <span style=\"color: #0000ff;\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-3-color\">physical switches<\/mark><\/span> which logically appears to be one switch.<\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"800\" height=\"454\" data-id=\"31039\" src=\"https:\/\/ipwithease.com\/wp-content\/uploads\/2015\/03\/Cisco-vPC-vs-VSS.jpg\" alt=\"Cisco vPC vs VSS\" class=\"wp-image-31039\" title=\"\" srcset=\"https:\/\/ipwithease.com\/wp-content\/uploads\/2015\/03\/Cisco-vPC-vs-VSS.jpg 800w, https:\/\/ipwithease.com\/wp-content\/uploads\/2015\/03\/Cisco-vPC-vs-VSS-768x436.jpg 768w, https:\/\/ipwithease.com\/wp-content\/uploads\/2015\/03\/Cisco-vPC-vs-VSS-300x170.jpg 300w, https:\/\/ipwithease.com\/wp-content\/uploads\/2015\/03\/Cisco-vPC-vs-VSS-600x341.jpg 600w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n<\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"what-is-v-pc-virtual-port-channel\">What is vPC (Virtual PortChannel)<\/h2>\n\n\n\n<p><strong>Technology: <\/strong>Used in Cisco Nexus switches.<\/p>\n\n\n\n<p><strong>Function: <\/strong>Allows two Nexus switches to appear as a single switch for Multi-Chassis Link Aggregation (MLAG).<\/p><div id=\"ipwit-229488729\" class=\"ipwit-content ipwit-entity-placement\"><div class=\"ipwit-adlabel\">Google ADs<\/div><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-1375203873676133\" crossorigin=\"anonymous\"><\/script><ins class=\"adsbygoogle\" style=\"display:block;\" data-ad-client=\"ca-pub-1375203873676133\" \ndata-ad-slot=\"2483378328\" \ndata-ad-format=\"auto\"><\/ins>\n<script> \n(adsbygoogle = window.adsbygoogle || []).push({}); \n<\/script>\n<\/div><br style=\"clear: both; display: block; float: none;\"\/>\n\n\n\n<p><strong>Control Plane:<\/strong> Each switch retains its own independent control plane.<\/p>\n\n\n\n<p><strong>Data Plane:<\/strong> Both switches forward traffic.<\/p>\n\n\n\n<p><strong>Peer Link:<\/strong> Used to synchronize MAC addresses, STP state, and other control plane information.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"pros\"><mark style=\"background-color:rgba(0, 0, 0, 0);color:#0af805\" class=\"has-inline-color\">Pros<\/mark><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>No spanning-tree blocking on vPC links.<\/li>\n\n\n\n<li>Redundant and load-balanced connections.<\/li>\n\n\n\n<li>Each switch has an independent control plane, which enhances failure domain isolation.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"cons\"><mark style=\"background-color:rgba(0, 0, 0, 0);color:#f60404\" class=\"has-inline-color\">Cons<\/mark><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Requires Nexus switches.<\/li>\n\n\n\n<li>Configuration and troubleshooting can be complex.<\/li>\n\n\n\n<li>Some protocols may not be fully synchronized due to separate control planes.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"what-is-vss-virtual-switching-system\">What is VSS (Virtual Switching System)<\/h2>\n\n\n\n<p><strong>Technology:<\/strong> Used in Cisco Catalyst switches.<\/p>\n\n\n\n<p><strong>Function:<\/strong> Merges two Catalyst switches into a single logical switch.<\/p>\n\n\n\n<p><strong>Control Plane:<\/strong> Only one active control plane; the second switch operates as a backup.<\/p>\n\n\n\n<p><strong>Data Plane:<\/strong> Both switches forward traffic.<\/p>\n\n\n\n<p><strong>Virtual Switch Link (VSL): <\/strong>Used to synchronize configuration and control plane information.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"pros-1\"><mark style=\"background-color:rgba(0, 0, 0, 0);color:#0af805\" class=\"has-inline-color\">PROS<\/mark><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Appears as a single switch to the network.<\/li>\n\n\n\n<li>Simplifies management and configuration.<\/li>\n\n\n\n<li>Eliminates spanning-tree blocked ports.<\/li>\n\n\n\n<li>Fully integrates control and data planes.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"cons-2\"><mark style=\"background-color:rgba(0, 0, 0, 0);color:#f70404\" class=\"has-inline-color\">CONS<\/mark><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>If the active switch fails, failover occurs (with some downtime).<\/li>\n\n\n\n<li>More complex initial setup.<\/li>\n\n\n\n<li>Only supported on specific Catalyst series switches.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"comparison-table-v-pc-vs-vss\">Comparison: vPC vs VSS<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"similarities\">Similarities<\/h3>\n\n\n\n<p>Lets try to understand the similarities of features and functions that necessitate the need to understand the differential points before choosing one.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Multi-Chassis Link Aggregation \u2013 <\/strong>Both vPC and VSS allow the aggregation of links across two physical switches, enabling a single logical connection to downstream devices.<\/li>\n\n\n\n<li><strong>Elimination of Spanning Tree Protocol (STP) Loops \u2013<\/strong> Both technologies create a loop-free topology, reducing reliance on STP and improving convergence times.<\/li>\n\n\n\n<li><strong>Increased Redundancy &amp; High Availability \u2013 <\/strong>They both enhance network resilience by ensuring that failure of one switch does not disrupt network connectivity.<\/li>\n\n\n\n<li><strong>Single Logical Switch Appearance \u2013 <\/strong>Both present two physical switches as a single logical entity to connected devices, simplifying network design and operations.<\/li>\n\n\n\n<li><strong>Faster Convergence \u2013<\/strong> In case of a link or switch failure, both technologies provide fast recovery times, ensuring minimal disruption to traffic flow.<\/li>\n\n\n\n<li><strong>Load Balancing &amp; Efficient Traffic Distribution \u2013<\/strong> Both vPC and VSS enable traffic load balancing across multiple links, improving bandwidth utilization and network performance.<\/li>\n\n\n\n<li><strong>Simplified Network Management \u2013 <\/strong>Both reduce administrative complexity by consolidating switch management and reducing the number of control planes.<\/li>\n\n\n\n<li><strong>Elimination of First Hop Redundancy Protocols (FHRPs) \u2013 <\/strong>In both technologies, connected devices see a single logical switch, eliminating the need for protocols like HSRP, VRRP, or GLBP between the two switches.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"differences\">Differences<\/h3>\n\n\n\n<p>The Differentiation between both the feature set is tabled below \u2013<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th><strong>VPC<\/strong><\/th><th><strong>VSS<\/strong><\/th><\/tr><\/thead><tbody><tr><td>Feature specific to Nexus<\/td><td>Feature specific to catalyst 6500,4500 Series<\/td><\/tr><tr><td>Separate control plane for both switches.<\/td><td>2 Switches merge to form 1 logical Switch with a single control plane.<\/td><\/tr><tr><td>Separate IP for each switch management and configuration.<\/td><td>Single IP for management and configuration of 1 Logical Unit (2 Physical Chassis)<\/td><\/tr><tr><td>HSRP is required.<\/td><td>First Hop Redundancy Protocol like HSRP not required.<\/td><\/tr><tr><td>Separate instance of STP, FHRP, IGP, BGP etc. will be required on each physical Switch of VPC.<\/td><td>Same instance of STP, FHRP, IGP, BGP etc. will be used on each physical Switch of VSS.<\/td><\/tr><tr><td>Both the switches are active and work individually. Only from VPC perspective are they elected primary and secondary.<\/td><td>Switches are always primary and secondary from all aspects.<\/td><\/tr><tr><td>Supports L2 Port Channels<\/td><td>Supports L3 Port Channels<\/td><\/tr><tr><td>Supports LACP<\/td><td>Supports PAGP and LACP<\/td><\/tr><tr><td>Control messages are carried by CFS over Peer Link and a Peer keep alive link is used to check heartbeats and detect dual-active condition<\/td><td>Control messages and Data frames flow between active and standby via VSL<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p><strong>Download the comparison table <span style=\"color: #0000ff;\"><a style=\"color: #0000ff;\" href=\"https:\/\/ipwithease.com\/wp-content\/uploads\/2015\/03\/VPC-VS-VSS-TABLE-NEW.jpg\" target=\"_blank\" rel=\"noopener noreferrer\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">vpc vs vss<\/mark><\/a><\/span><\/strong><\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"which-one-should-you-choose\">Which One Should You Choose?<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use vPC if you are deploying Cisco Nexus switches in a data center and need active-active forwarding.<\/li>\n\n\n\n<li>Use VSS if you are deploying Cisco Catalyst switches in a campus\/LAN environment and prefer a single logical switch with a simpler control plane.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"continue-reading\"><span style=\"color: #ff6600;\">Continue Reading:<\/span><\/h2>\n\n\n\n<p><span style=\"color: #0000ff;\"><em><strong><a style=\"color: #0000ff;\" href=\"https:\/\/ipwithease.com\/how-vpc-differs-from-vpc\/\" target=\"_blank\" rel=\"noopener noreferrer\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">How VPC+ differs from VPC?<\/mark><\/a><\/strong><\/em><\/span><\/p>\n\n\n\n<p><span style=\"color: #0000ff;\"><em><strong><a style=\"color: #0000ff;\" href=\"https:\/\/ipwithease.com\/vpc-architecture-and-components\/\" target=\"_blank\" rel=\"noopener noreferrer\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">Nexus VPC Architecture and Components<\/mark><\/a><\/strong><\/em><\/span><\/p>\n<h3>ABOUT THE AUTHOR<\/h3><div id=\"ipwit-3232338340\" class=\"ipwit-post-end-ad ipwit-entity-placement\"><script async src=\"\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-1375203873676133\" crossorigin=\"anonymous\"><\/script><ins class=\"adsbygoogle\" style=\"display:block;\" data-ad-client=\"ca-pub-1375203873676133\" \ndata-ad-slot=\"2483378328\" \ndata-ad-format=\"auto\"><\/ins>\n<script> \n(adsbygoogle = window.adsbygoogle || []).push({}); \n<\/script>\n<\/div><br style=\"clear: both; display: block; float: none;\"\/>","protected":false},"excerpt":{"rendered":"<p>Both VPC and VSS are used basically to support multi-chassis ether-channel that means we can create a port-channel whose one [&hellip;]<\/p>\n","protected":false},"author":782,"featured_media":31039,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[177],"tags":[75,34,35,29],"class_list":["post-436","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-routing-switching","tag-comparison","tag-high-availability","tag-redundancy","tag-switching"],"_links":{"self":[{"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/posts\/436","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/users\/782"}],"replies":[{"embeddable":true,"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/comments?post=436"}],"version-history":[{"count":0,"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/posts\/436\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/media\/31039"}],"wp:attachment":[{"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/media?parent=436"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/categories?post=436"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ipwithease.com\/wp-json\/wp\/v2\/tags?post=436"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}