{"id":5394,"date":"2017-09-13T09:25:49","date_gmt":"2017-09-13T09:25:49","guid":{"rendered":"http:\/\/32478000127144839.blog.com.gr\/route-servers\/"},"modified":"2025-10-14T12:19:10","modified_gmt":"2025-10-14T12:19:10","slug":"route-servers","status":"publish","type":"page","link":"https:\/\/www.gr-ix.gr\/el\/route-servers\/","title":{"rendered":"Route Servers"},"content":{"rendered":"<p><div class=\"wrapper  \" style=\"\" >\n\t\t\t\t<div class=\"row \"><div class=\"col-xs-12 col-sm-12 col-md-12 col-lg-12\"><div class='blox_element tt_text_content  '><h3 class=\"element_title\">Overview<\/h3>\n<p data-start=\"138\" data-end=\"295\">The use of route servers at GR-IX simplifies the exchange of routing information between members and accelerates the onboarding process for new participants.<\/p>\n<p data-start=\"297\" data-end=\"615\">These servers function as BGP proxies, removing the need for establishing direct peerings among members. They relay BGP announcements based on each participant\u2019s policy, without modifying the BGP next-hop or AS-PATH. This means they are involved in the control plane but not in the data plane of the exchanged traffic.<\/p>\n<p data-start=\"617\" data-end=\"878\">They support MD5 authentication and handle prefix advertisements according to member-defined rules, expressed via BGP communities. All BGP sessions are passive\u2014operating in server mode, listening on TCP port 179, and never initiating outbound connections.<\/p>\n<p data-start=\"880\" data-end=\"1108\">Participation is encouraged but not mandatory. Members should not assume universal connectivity or willingness to peer via these servers. Even when using them, bilateral business agreements may still be required between parties.<\/p>\n<p>&nbsp;<\/p><\/div><div class='blox_element tt_text_content  '><h3 class=\"element_title\">Recommendations for the members<\/h3>\n<ul>\n<li>Peering with all route servers is recommended (although not mandatory).<\/li>\n<li>For members with multiple routers connected to GR-IX, it is recommended that each of these routers connect to all route servers, and that each of those routers implement the same import\/export policy for all of these peerings.<\/li>\n<li>Members are <em><span style=\"text-decoration: underline;\">not<\/span><\/em> discouraged from setting up direct bgp peerings with other key members, in addition to peering with them through the route servers.<\/li>\n<\/ul>\n<p>&nbsp;<\/p><\/div><div class='blox_element tt_text_content  '><h3 class=\"element_title\">How to connect<\/h3><\/div><\/div><\/div>\n\t\t\t<\/div><div class=\"wrapper  \" style=\"\" >\n\t\t\t\t<div class=\"row \"><div class=\"col-xs-12 col-xxs-6 col-sm-6 col-md-6 col-lg-6\"><h3 class='element_title'>GR-IX::Athens<\/h3>\n\t\t\t<div class='blox_element blox_elem_content_box  blox_elem_content_box_default  ' style=''>\n\t\t\t\t\n\t\t\t\t<div class='blox_elem_content_box_content'>\n\t\t\t\t\t\n<p>&nbsp;<\/p>\n<table class=\"table\" border=\"0\" cellspacing=\"0\">\n<thead>\n<tr>\n<th class=\"orange\"><span style=\"font-size: 16px;\">Route Server<\/span><\/th>\n<th class=\"orange\"><span style=\"font-size: 16px;\">AS Number<\/span><\/th>\n<th class=\"orange\"><span style=\"font-size: 16px;\">IPv4 Address<\/span><\/th>\n<th class=\"orange\"><span style=\"font-size: 16px;\">IPv6 Address<\/span><\/th>\n<th class=\"orange\"><span style=\"font-size: 16px;\">PoP<\/span><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>rs0.gr-ix.gr<\/td>\n<td>50745<\/td>\n<td>176.126.38.120<\/td>\n<td>2001:7f8:6e::120<\/td>\n<td>ATH02 &#8211; Digital Realty (DLR)<\/td>\n<\/tr>\n<tr>\n<td>rs1.gr-ix.gr<\/td>\n<td>50745<\/td>\n<td>176.126.38.121<\/td>\n<td>2001:7f8:6e::121<\/td>\n<td>ATH01 &#8211; National Hellenic Research Foundation (NHRF)<\/td>\n<\/tr>\n<tr>\n<td>rs2.gr-ix.gr<\/td>\n<td>50745<\/td>\n<td>176.126.38.117<\/td>\n<td>2001:7f8:6e::117<\/td>\n<td>ATH03 &#8211; Telecom Italia Sparkle (TIS)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n\t\t\t\t<\/div>\n\t\t\t<\/div><\/div><div class=\"col-xs-12 col-xxs-6 col-sm-6 col-md-6 col-lg-6\"><h3 class='element_title'>GR-IX::Thessaloniki<\/h3>\n\t\t\t<div class='blox_element blox_elem_content_box  blox_elem_content_box_default  ' style=''>\n\t\t\t\t\n\t\t\t\t<div class='blox_elem_content_box_content'>\n\t\t\t\t\t\n<p>&nbsp;<\/p>\n<table class=\"table\" border=\"0\" cellspacing=\"0\">\n<thead>\n<tr>\n<th class=\"orange\"><span style=\"font-size: 16px;\">Route Server<\/span><\/th>\n<th class=\"orange\"><span style=\"font-size: 16px;\">AS Number<\/span><\/th>\n<th class=\"orange\"><span style=\"font-size: 16px;\">IPv4 Address<\/span><\/th>\n<th class=\"orange\"><span style=\"font-size: 16px;\">IPv6 Address<\/span><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>rs0.thess.gr-ix.gr<\/td>\n<td>50745<\/td>\n<td>185.1.123.120<\/td>\n<td>2001:7f8:ce::120<\/td>\n<\/tr>\n<tr>\n<td>rs1.thess.gr-ix.gr<\/td>\n<td>50745<\/td>\n<td>185.1.123.121<\/td>\n<td>2001:7f8:ce::121<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n\t\t\t\t<\/div>\n\t\t\t<\/div><\/div><\/div>\n\t\t\t<\/div><div class=\"wrapper  \" style=\"\" >\n\t\t\t\t<div class=\"row \"><div class=\"col-xs-12 col-sm-12 col-md-12 col-lg-12\"><div class='blox_element tt_text_content  '>\n<p>&nbsp;<\/p>\n<p>The route servers implement the following BGP timers:<code><br \/>\nkeepalive 10<br \/>\nhold-time 30<\/code><\/p>\n<p>&nbsp;<\/p>\n<p><em>(Note: Timers are part of the bgp negotiation with the peer; the larger values apply)<\/em><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Tip:<\/strong> In some BGP implementations, the BGP process will discard by default any prefixes received from eBGP peers if the peer&#8217;s autonomous system (AS) number does not appear first in the AS_PATH. This is always the case when peering with a route server, as the route server is configured to &#8220;hide&#8221; its AS number. Hence, when peering with the route servers, this check must be disabled (i.e. with a\u00a0<code>no bgp enforce-first-as<\/code>\u00a0on a\u00a0<code>Cisco<\/code>\u00a0router)<\/p>\n<p>&nbsp;<\/p><\/div><div class='blox_element tt_text_content  '>\n<p>&nbsp;<\/p>\n<p>BGP communities can be used in order to control the members where a prefix is advertised.<\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li>By default, the route server will advertise each prefix to all connected members.<\/li>\n<li>Standard community\u00a0<code>50745:PEER-AS<\/code>\u00a0or extended community\u00a0<code>route_target:50745:PEER-AS<\/code>\u00a0(depending on whether the PEER AS is 2- or 4-byte) can be used to exclude announcing this prefix to PEER-AS.<\/li>\n<li>Community\u00a0<code>50745:0<\/code>\u00a0can invert the policy for a prefix; that is, the prefix will be advertised only to the AS&#8217;es identified by the\u00a0<code>(route_target:)50745:PEER-AS<\/code>\u00a0communities on the prefix.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>Note that this is a per-prefix behavior, i.e. each prefix may implement a different policy based on its own communities.<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"text-decoration: underline;\"><strong>Note:<\/strong><\/span> also that there is no way for a member to block the incoming advertisements on the route-server level; this has to be done by ingress BGP filters on its own equipment.<\/p>\n<p>&nbsp;<\/p><\/div><h3 class='element_title'>BGP Communities<\/h3>\n\t\t\t<div class='blox_element blox_elem_content_box  blox_elem_content_box_default  ' style=''>\n\t\t\t\t\n\t\t\t\t<div class='blox_elem_content_box_content'>\n\t\t\t\t\t\n<p>&nbsp;<\/p>\n<table class=\"table\" border=\"0\" cellspacing=\"0\">\n<thead>\n<tr>\n<th class=\"orange\"><span style=\"font-size: 16px;\">Community<\/span><\/th>\n<th class=\"orange\"><span style=\"font-size: 16px;\">Purpose<\/span><\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td colspan=\"2\"><b>Advertisement Control:<\/b><\/td>\n<\/tr>\n<tr>\n<td>50745:PeerAS (for 16-bit AS numbers) or route_target:50745:PeerAS (for 16-bit or 32-bit AS numbers)<\/td>\n<td>Do not advertise to PeerAS<\/td>\n<\/tr>\n<tr>\n<td>50745:0 or route_target:50745:0<\/td>\n<td>Inverse policy (do not advertise to any peers, except from those defined with RSasn:PeerAS)<\/td>\n<\/tr>\n<tr>\n<td colspan=\"2\"><b>Prepending (communities can be combined)<\/b><\/td>\n<\/tr>\n<tr>\n<td>50745:65501<\/td>\n<td>Prepend 50745 one time<\/td>\n<\/tr>\n<tr>\n<td>50745:65502<\/td>\n<td>Prepend 50745 two times<\/td>\n<\/tr>\n<tr>\n<td>50745:65503<\/td>\n<td>Prepend 50745 three times<\/td>\n<\/tr>\n<tr>\n<td colspan=\"2\"><b>MED handling<\/b><\/td>\n<\/tr>\n<tr>\n<td>50745:65000<\/td>\n<td>Do not alter incoming MED for IX switching optimization<\/td>\n<\/tr>\n<tr>\n<td colspan=\"2\"><b>Marking (performed by the route servers)<\/b><\/td>\n<\/tr>\n<tr>\n<td>50745:65101<\/td>\n<td>Prefix received by a peering at ATH01 (EIE)<\/td>\n<\/tr>\n<tr>\n<td>50745:65102<\/td>\n<td>Prefix received by a peering at ATH02 (DLR)<\/td>\n<\/tr>\n<tr>\n<td>50745:65103<\/td>\n<td>Prefix received by a peering at ATH03 (TIS)<\/td>\n<\/tr>\n<tr>\n<td>50745:65111<\/td>\n<td>Prefix received by a peering at THESS01 (SNC)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n\t\t\t\t<\/div>\n\t\t\t<\/div><div class='blox_element tt_text_content  '><h3 class=\"element_title\">Processing of prefixes<\/h3>\n<p>&nbsp;<\/p>\n<p><span style=\"text-decoration: underline;\"><strong>Received prefixes<\/strong><\/span><\/p>\n<p>&nbsp;<\/p>\n<p>The route server will not accept:<\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li>Prefixes with next-hop different than the peers&#8217; ip(v4\/v6) address.<\/li>\n<li>Martians and other unexpected routes:\n<ul>\n<li>v4: 10.0.0.0\/8+, 169.254.0.0\/16+, 172.16.0.0\/12+, 192.0.0.0\/24+, 192.0.2.0\/24+, 192.168.0.0\/16+, 198.18.0.0\/15+, 198.51.100.0\/24+, 203.0.113.0\/24+, 224.0.0.0\/4+, 240.0.0.0\/4+, 0.0.0.0\/32, 0.0.0.0\/0(28-32), 0.0.0.0\/0(0,7)<\/li>\n<li>v6: ::\/0, ::\/96, ::\/128, ::1\/128, ::ffff:0.0.0.0\/96+, ::224.0.0.0\/100+, ::127.0.0.0\/104+, ::0.0.0.0\/104+, ::255.0.0.0\/104+, 0000::\/8+, 0200::\/7+,3ffe::\/16+, 2001:db8::\/32+, 2002:e000::\/20+, 2002:7f00::\/24+, 2002:0000::\/24+, 2002:ff00::\/24+, 2002:0a00::\/24+, 2002:ac10::\/28+, 2002:c0a8::\/3+, fc00::\/7+, fe80::\/10+, fec0::\/10+, ff00::\/8+<\/li>\n<\/ul>\n<\/li>\n<li>Prefixes\n<ul>\n<li>with an RPKI\u00a0INVALID status<\/li>\n<li>with the last AS in the AS-PATH not included in the member&#8217;s AS-SET (as defined in the <a href=\"http:\/\/portal.gr-ix.gr\/\" target=\"_blank\" rel=\"noopener\">members portal<\/a>), and<\/li>\n<li>without a corresponding route object of same length that originates from an AS in the member&#8217;s AS-SET<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>In addition, the number of received prefixes is capped by the maximum prefixes defined per member in the <a href=\"http:\/\/portal.gr-ix.gr\/\" target=\"_blank\" rel=\"noopener\">members portal<\/a>.<\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"text-decoration: underline;\">Advertised prefixes<\/span><\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>The route servers:<\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li>Will advertise to all peers except PeerAS all prefixes that contain\u00a0<code>50745:PeerAS<\/code><\/li>\n<li>Will advertise only to PeerAS all prefixes that contain both\u00a0<code>50745:0<\/code>\u00a0and\u00a0<code>50745:PeerAS<\/code><\/li>\n<li>Will NOT advertise to any peer all prefixes that contain only\u00a0<code>50745:0<\/code><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>If more than one candidate exists for the same prefix, the route selection will take place as follows:<\/p>\n<p>&nbsp;<\/p>\n<ol>\n<li>The prefix with the shortest AS path will be selected<\/li>\n<li>The prefix with the best origin will be selected (IGP-&gt;EGP-&gt;incomplete)<\/li>\n<li>For prefixes of the same Peer (same first AS in the AS-PATH), the prefix with the lower MED will be selected (no MED=0)<\/li>\n<li>The older (more stable) prefix will be selected<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<p>Note: As different prefixes may be eligible to be advertised to different peers, different best candidates for the same prefix may be advertised to different members.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>By default, the route servers will change MED in order to optimise routing<\/strong> (i.e, between two same prefixes of the same AS, the closer (in terms of switching hops) will be selected). This behavior can be overridden using the\u00a0community <code>50745:65000<\/code>; in that case MED will be respected by the route server and will be preserved at the outgoing advertisements.<\/p>\n<p>&nbsp;<\/p>\n<p>The route server will always preserve the AS-PATH and next-hop.<\/p>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-2826 size-full\" src=\"https:\/\/www.gr-ix.gr\/wp-content\/uploads\/2017\/09\/grix-route-servers.png\" alt=\"grix-route-servers\" width=\"928\" height=\"699\" srcset=\"https:\/\/www.gr-ix.gr\/wp-content\/uploads\/2017\/09\/grix-route-servers.png 928w, https:\/\/www.gr-ix.gr\/wp-content\/uploads\/2017\/09\/grix-route-servers-300x226.png 300w, https:\/\/www.gr-ix.gr\/wp-content\/uploads\/2017\/09\/grix-route-servers-768x578.png 768w\" sizes=\"auto, (max-width: 928px) 100vw, 928px\" \/><\/p>\n<p>&nbsp;<\/p><\/div><div class='blox_element tt_text_content  '><h3 class=\"element_title\">MD5 Authentication<\/h3>\n<p>&nbsp;<\/p>\n<p>The route servers support MD5 authentication of the BGP peerings. In order to enable authentication please\u00a0<a href=\"https:\/\/portal.gr-ix.gr\/static\/support\">contact our helpdesk<\/a><\/p>\n<p>&nbsp;<\/p><\/div><div class='blox_element tt_text_content  '><h3 class=\"element_title\">Update Schedule<\/h3>\n<p>&nbsp;<\/p>\n<p>The route servers are updated in a regular basis in order to reflect changes in the IRRDBs (eg new AS numbers within a macro, new prefixes originating from an AS) or changes within the\u00a0<a href=\"http:\/\/portal.gr-ix.gr\/\" target=\"_blank\" rel=\"noopener\">members portal<\/a> (eg new MD5 password, new macro etc). The update scedule for the route servers is different in order to minimize the propagation of errors. The update schedule is as follows:<\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li><strong>rs0:<\/strong> Every two hours, between 10.00 and 14.00 (local time), Monday to Friday<\/li>\n<li><strong>rs1:<\/strong> Every two hours, between 12.00 and 16.00 (local time), Monday to Friday<\/li>\n<li><strong>rs2:<\/strong> Every two hours, between 11.00 and 15.00 (local time), Monday to Friday<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>You can see the time of the last reconfiguration of each route server through the <a title=\"GR-IX route server looking glass\" href=\"http:\/\/portal.gr-ix.gr\/lg\" target=\"_blank\" rel=\"noopener\">route server looking glass<\/a>.<\/p>\n<p>&nbsp;<\/p><\/div><div class='blox_element tt_text_content  '><h3 class=\"element_title\">Debugging<\/h3>\n<p>&nbsp;<\/p>\n<p>Two debugging tools are offered:<\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li>The <a title=\"GR-IX route server looking glass\" href=\"http:\/\/portal.gr-ix.gr\/lg\" target=\"_blank\" rel=\"noopener\">route server looking glass<\/a> where you can check the prefixes and their properties (as_path, communities, next-hop etc) in each of the routing tables of each route server<\/li>\n<li>A Route Server Prefix report tool that reports prefixes accepted, rejected and acceptable (but not announced) prefixes. This tool is available for members only through the <a href=\"http:\/\/portal.gr-ix.gr\/\" target=\"_blank\" rel=\"noopener\">GR-IX portal<\/a>.<\/li>\n<\/ul>\n<p>&nbsp;<\/p><\/div><\/div><\/div>\n\t\t\t<\/div><\/p>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":4,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","footnotes":""},"class_list":["post-5394","page","type-page","status-publish","hentry"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"small":false,"thumb":false,"metro-small":false,"metro-horizontal":false,"metro-large":false,"relatedposts":false},"uagb_author_info":{"display_name":"vickyk","author_link":"https:\/\/www.gr-ix.gr\/el\/author\/vickyk\/"},"uagb_comment_info":0,"uagb_excerpt":null,"_links":{"self":[{"href":"https:\/\/www.gr-ix.gr\/el\/wp-json\/wp\/v2\/pages\/5394","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gr-ix.gr\/el\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.gr-ix.gr\/el\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.gr-ix.gr\/el\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gr-ix.gr\/el\/wp-json\/wp\/v2\/comments?post=5394"}],"version-history":[{"count":10,"href":"https:\/\/www.gr-ix.gr\/el\/wp-json\/wp\/v2\/pages\/5394\/revisions"}],"predecessor-version":[{"id":6379,"href":"https:\/\/www.gr-ix.gr\/el\/wp-json\/wp\/v2\/pages\/5394\/revisions\/6379"}],"wp:attachment":[{"href":"https:\/\/www.gr-ix.gr\/el\/wp-json\/wp\/v2\/media?parent=5394"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}