As a service provider you have a mountain of terms to deal with. As you dive into the realm of BGP, you will hear many terms in regards to peers. \u00a0Knowing their names AND your definition of them will serve you well. \u00a0I emphasized the and in the last sentence because many people have different definitions of what these terms means. This can be due to how long they have been dealing with networks, what they do with them, and other such things. \u00a0For example, many content providers use the term transit differently than an ISP. \u00a0So, let’s get on to it.<\/p>\n
Transit or upstream<\/strong> Downstream<\/strong> Peer<\/strong> Local or Private Peer<\/strong> I have trained myself to qualify what I mean by a peer when talking about them. I will often say a “transit peer” or a “local peer”. This helps to add a little bit of clarity to what you mean.<\/p>\n Why is this all important? For one, it helps with keeping everyone on the same page when talking about peering. \u00a0I had a case a few weeks ago where a Content provider and I wasted configuration time because our definition of transit was different. \u00a0Secondly, you want to be able to classify your peers so you can apply different filter rules to them. For example, with a downstream peer you only want to accept the IP space they have shown you which is their own. \u00a0That way you are not sending your own transit traffic over their network. This would be bad. \u00a0However, if you are accepting full routes from your transit provider, you want your filters to accept much more IP than a downstream provider. So if you have a team being able to be on the same page about peers will help when it comes to writing filters, and how your routers “treat” the peer in terms of access lists, route filters, etc.<\/p>\n","protected":false},"excerpt":{"rendered":" As a service provider you have a mountain of terms to deal with. As you dive into the realm of BGP, you will hear many terms in regards to peers. \u00a0Knowing their names AND your definition of them will serve you well. \u00a0I emphasized the and in the last sentence because many people have different […]<\/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":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[212,17],"tags":[213,214,100,43,215,104],"jetpack_publicize_connections":[],"aioseo_notices":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p6VLMf-5Z","jetpack-related-posts":[{"id":1497,"url":"http:\/\/www.mtin.net\/blog\/bgp-local-pref-and-you\/","url_meta":{"origin":371,"position":0},"title":"BGP local Pref and you","author":"j2sw","date":"January 7, 2017","format":false,"excerpt":"One of the bgp topics that comes up from time to time is what does \"bgp local-pref\" do for me? The short answer is it allows you to prefer which direction a traffic will flow to a given destination. How can this help you? Well before we start, remember the\u2026","rel":"","context":"In "BGP"","block_context":{"text":"BGP","link":"http:\/\/www.mtin.net\/blog\/category\/networking\/bgp\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1309,"url":"http:\/\/www.mtin.net\/blog\/how-i-learned-to-love-bgp-communities-and-so-can-you\/","url_meta":{"origin":371,"position":1},"title":"How I learned to love BGP communities, and so can you","author":"j2sw","date":"July 6, 2016","format":false,"excerpt":"BGP communities can be a powerful, but almost mystical thing. \u00a0If you aren't familiar with communities start here at Wikipedia. \u00a0For the purpose of part one of this article we will talk about communities and how they can be utilized for traffic coming into your network.\u00a0Part two of this article\u2026","rel":"","context":"In "BGP"","block_context":{"text":"BGP","link":"http:\/\/www.mtin.net\/blog\/category\/networking\/bgp\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":458,"url":"http:\/\/www.mtin.net\/blog\/ip-space-terms-to-know\/","url_meta":{"origin":371,"position":2},"title":"IP space terms to know","author":"j2sw","date":"December 5, 2015","format":false,"excerpt":"When you are talking about the type of assigned Public IP space you have there are a couple of terms that are handy to know. Provider assigned (PA) space. This is space assigned by your upstream provider. These \"belong\" to someone you are buying services from. If you wish to\u2026","rel":"","context":"In "BGP"","block_context":{"text":"BGP","link":"http:\/\/www.mtin.net\/blog\/category\/networking\/bgp\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1832,"url":"http:\/\/www.mtin.net\/blog\/the-problem-with-peering-from-a-logistics-standpoint\/","url_meta":{"origin":371,"position":3},"title":"The problem with peering from a logistics standpoint","author":"j2sw","date":"September 29, 2017","format":false,"excerpt":"Many ISPs run into this problem as part of their growing pains.\u00a0 This scenario usually starts happening with their third or 4th peer. Scenario.\u00a0 ISP grows beyond the single connection they have.\u00a0 This can be 10 meg, 100 meg, gig or whatever.\u00a0 They start out looking for redundancy. The ISP\u2026","rel":"","context":"In "BGP"","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\/2017\/09\/dreamstime_xs_87568893.jpg?fit=480%2C320&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":365,"url":"http:\/\/www.mtin.net\/blog\/basic-mikrotik-bgp-filter-rules\/","url_meta":{"origin":371,"position":4},"title":"Basic Mikrotik BGP filter rules","author":"j2sw","date":"October 29, 2015","format":false,"excerpt":"Below are some basic Filter Rules for Mikrotik BGP filtering. \u00a0These are not complex and can be very easily implemented on your BGP peers. Before we get to the code there are a few assumptions 1.Your own IP space in this example is 1.1.1.0\/22 2.These filters are not fancy and\u2026","rel":"","context":"In "Mikrotik"","block_context":{"text":"Mikrotik","link":"http:\/\/www.mtin.net\/blog\/category\/mikrotik\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":434,"url":"http:\/\/www.mtin.net\/blog\/simple-bgp-by-qrator\/","url_meta":{"origin":371,"position":5},"title":"Simple BGP by Qrator","author":"j2sw","date":"November 17, 2015","format":false,"excerpt":"so the folks over at Qrator have proposed some additions to BGP. At the heart of this is the addition of roles in a BGP session. You would have four possible roles: customer, provider,peer, and internal. You can learn some more about this at https:\/\/radar.qrator.net\/tools\/simple-bgp","rel":"","context":"In "Networking"","block_context":{"text":"Networking","link":"http:\/\/www.mtin.net\/blog\/category\/networking\/"},"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\/371"}],"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=371"}],"version-history":[{"count":10,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/posts\/371\/revisions"}],"predecessor-version":[{"id":381,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/posts\/371\/revisions\/381"}],"wp:attachment":[{"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/media?parent=371"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/categories?post=371"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.mtin.net\/blog\/wp-json\/wp\/v2\/tags?post=371"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nThis is what you will hear most often. \u00a0A transit peer is someone who you go “through” in order to reach the internet. \u00a0You transit their network to reach other networks. \u00a0Many folks use the term “upstream provider” when talking about someone they buy their internet from.<\/p>\n
\nSomeone who is “downstream” is someone \u00a0you are providing Internet to. \u00a0They are “transiting” your network to reach the Internet. \u00a0This is typically someone you are selling Internet to.<\/p>\n
\nThis is the term which probably needs the most clarification when communicating with others about how your BGP is setup. \u00a0A peer is most often used as a generic term, much like Soda (or pop depending on where you are from). For example someone could say:
\n“I have a peer setup with my upstream provider who is Cogent.” This is perfectly acceptable when used with the addition of “my upstream provider”. \u00a0Peers are often referred to as “neighbors” or “BGP neighbors”.<\/p>\n
\nSo what is a local peer? A local peer is a network you are “peering” with and you are only exchanging routes which are their own or their downstream networks. \u00a0A local peer usually happens most often at an Internet Exchange (IX) but can happen in common points where networks meet. The most important thing that defines a local peer is you are not using them to reach IP space which is not being advertised form their ASN. \u00a0 Your peering relationship is just between the two of you. This gets a little muddy when you are peering on an IX, but thats being picky.<\/p>\n