{"id":452,"date":"2015-11-29T17:59:58","date_gmt":"2015-11-29T17:59:58","guid":{"rendered":"http:\/\/www.mtin.net\/blog\/?p=452"},"modified":"2015-11-29T17:59:58","modified_gmt":"2015-11-29T17:59:58","slug":"rfcs-you-need-to-know-rfc-2796-bgp-route-reflection","status":"publish","type":"post","link":"http:\/\/www.mtin.net\/blog\/rfcs-you-need-to-know-rfc-2796-bgp-route-reflection\/","title":{"rendered":"RFC&#8217;s you need to know: RFC 2796 BGP Route Reflection"},"content":{"rendered":"<p><a href=\"https:\/\/tools.ietf.org\/html\/rfc2796\">https:\/\/tools.ietf.org\/html\/rfc2796<\/a><\/p>\n<pre>Currently in the Internet, BGP deployments are configured such that all BGP speakers within a single AS must be fully meshed and any external routing information must be re-distributed to all other routers within that AS. For n BGP speakers within an AS that requires to maintain n*(n-1)\/2 unique IBGP sessions. This \"full mesh\" requirement clearly does not scale when there are a large number of IBGP speakers each exchanging a large volume of routing information, as is common in many of todays internet networks.<\/pre>\n<pre>This scaling problem has been well documented and a number of proposals have been made to alleviate this [<a title=\"&quot;A BGP\/IDRP Route Server alternative to a full mesh routing&quot;\" href=\"https:\/\/tools.ietf.org\/html\/rfc2796#ref-2\">2<\/a>,<a title=\"&quot;Limited Autonomous System Confederations for BGP&quot;\" href=\"https:\/\/tools.ietf.org\/html\/rfc2796#ref-3\">3<\/a>]. This document represents another alternative in alleviating the need for a \"full mesh\" and is known as \"Route Reflection\". This approach allows a BGP speaker (known as \"Route Reflector\") to advertise IBGP learned routes to certain IBGP peers. It represents a change in the commonly understood concept of IBGP, and the addition of two new optional transitive BGP attributes to prevent loops in routing updates.<\/pre>\n<pre class=\"newpage\"><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>https:\/\/tools.ietf.org\/html\/rfc2796 Currently in the Internet, BGP deployments are configured such that all BGP speakers within a single AS must be fully meshed and any external routing information must be re-distributed to all other routers within that AS. For n BGP speakers within an AS that requires to maintain n*(n-1)\/2 unique IBGP sessions. This &#8220;full mesh&#8221; [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[212,17],"tags":[266,13,265,264],"jetpack_publicize_connections":[],"aioseo_notices":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p6VLMf-7i","jetpack-related-posts":[{"id":443,"url":"http:\/\/www.mtin.net\/blog\/how-does-bgp-select-which-route\/","url_meta":{"origin":452,"position":0},"title":"How does BGP select which route?","author":"j2sw","date":"November 26, 2015","format":false,"excerpt":"BGP can be a complex and almost mystical protocol. For those of you who are trying to determine how BGP selects which route here is your guide. Before we get into it a couple of things to keep in mind. First, BGP is not a multipath routing protocol. This is\u2026","rel":"","context":"In &quot;BGP&quot;","block_context":{"text":"BGP","link":"http:\/\/www.mtin.net\/blog\/category\/networking\/bgp\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":2267,"url":"http:\/\/www.mtin.net\/blog\/what-is-a-bgp-confederation\/","url_meta":{"origin":452,"position":1},"title":"What is a BGP Confederation?","author":"j2sw","date":"May 15, 2018","format":false,"excerpt":"In\u00a0network routing,\u00a0BGP confederation\u00a0is a method to use\u00a0Border Gateway Protocol\u00a0(BGP) to subdivide a single\u00a0autonomous system\u00a0(AS) into multiple internal sub-AS's, yet still advertise as a single AS to\u00a0external peers. This is done to reduce the number of entries in the iBGP routing table.\u00a0 If you are familiar with breaking OSPF domains up\u2026","rel":"","context":"In \"BGP\"","block_context":{"text":"BGP","link":"http:\/\/www.mtin.net\/blog\/tag\/bgp\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.mtin.net\/blog\/wp-content\/uploads\/2018\/05\/atasco.jpg?fit=1122%2C711&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.mtin.net\/blog\/wp-content\/uploads\/2018\/05\/atasco.jpg?fit=1122%2C711&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.mtin.net\/blog\/wp-content\/uploads\/2018\/05\/atasco.jpg?fit=1122%2C711&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.mtin.net\/blog\/wp-content\/uploads\/2018\/05\/atasco.jpg?fit=1122%2C711&resize=1050%2C600 3x"},"classes":[]},{"id":2670,"url":"http:\/\/www.mtin.net\/blog\/bgp-monitoring-rfc-7854\/","url_meta":{"origin":452,"position":2},"title":"BGP Monitoring RFC 7854","author":"j2sw","date":"December 4, 2018","format":false,"excerpt":"https:\/\/tools.ietf.org\/html\/rfc7854 This document defines the BGP Monitoring Protocol (BMP), which can be used to monitor BGP sessions. BMP is intended to provide a convenient interface for obtaining route views. Prior to the introduction of BMP, screen scraping was the most commonly used approach to obtaining such views. The design goals\u2026","rel":"","context":"In &quot;BGP&quot;","block_context":{"text":"BGP","link":"http:\/\/www.mtin.net\/blog\/category\/networking\/bgp\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.mtin.net\/blog\/wp-content\/uploads\/2018\/05\/atasco.jpg?fit=1122%2C711&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.mtin.net\/blog\/wp-content\/uploads\/2018\/05\/atasco.jpg?fit=1122%2C711&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.mtin.net\/blog\/wp-content\/uploads\/2018\/05\/atasco.jpg?fit=1122%2C711&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.mtin.net\/blog\/wp-content\/uploads\/2018\/05\/atasco.jpg?fit=1122%2C711&resize=1050%2C600 3x"},"classes":[]},{"id":183,"url":"http:\/\/www.mtin.net\/blog\/bgp-lockdown-hints\/","url_meta":{"origin":452,"position":3},"title":"BGP lockdown hints","author":"j2sw","date":"September 29, 2014","format":false,"excerpt":"As I am preparing talks for the upcoming WISPAPALOOZA 2014 in Las Vegas I am making some notes on advanced BGP. \u00a0If you are running BGP, and want to lock it down a little here are some general hints. \u00a0If you want more attend my session in Vegas or look\u2026","rel":"","context":"In &quot;Mikrotik&quot;","block_context":{"text":"Mikrotik","link":"http:\/\/www.mtin.net\/blog\/category\/mikrotik\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1377,"url":"http:\/\/www.mtin.net\/blog\/soft-reconfiguration-inbound\/","url_meta":{"origin":452,"position":4},"title":"Soft Reconfiguration inbound","author":"j2sw","date":"September 15, 2016","format":false,"excerpt":"Several people have been asking what soft Reconfiguration Inbound is on a BGP peer. In the dark days of BGP you had to tear down the BGP session and do a full reestablishment in order to bring it up. \u00a0What soft reconfiguration does is copies of all routes received (this\u2026","rel":"","context":"In &quot;BGP&quot;","block_context":{"text":"BGP","link":"http:\/\/www.mtin.net\/blog\/category\/networking\/bgp\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":132,"url":"http:\/\/www.mtin.net\/blog\/mtin-services\/","url_meta":{"origin":452,"position":5},"title":"MTIN Services","author":"j2sw","date":"August 26, 2014","format":false,"excerpt":"WISP and Wireline\/Fiber Design and Operation MPLS Design and Implementation Multicast Routing IGMP, PIM eBGP\/iBGP design\/implementation Cisco Routers 2800, 3600, 7200, 7600, ASR, ISR Cisco Switches 2950, 3550, 3560, 3750, 6500 Switching (Layer 2) STP, RSTP, EOIP, MSTP, VLAN \u2013 dot1q and q-in-q Routing (layer 3) OSPF, BGP, MPLS, L2VPN\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"jetpack_likes_enabled":true,"_links":{"self":[{"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/posts\/452"}],"collection":[{"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/comments?post=452"}],"version-history":[{"count":1,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/posts\/452\/revisions"}],"predecessor-version":[{"id":453,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/posts\/452\/revisions\/453"}],"wp:attachment":[{"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/media?parent=452"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/categories?post=452"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/tags?post=452"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}