AS16509 peering information and eBGP neighbors

interconnection points


Extensive peering arrangements are a critical component to providing outstanding connectivity and performance for the customers as well as increased service resilience through diversified routing.

Peering is the bedrock of every network and all service providers actively expand their peering capacity in line with traffic growth to maintain world class performance.

AS16509 Configuration for iBGP and eBGP

BGP is an exterior gateway protocol (EGP), used to perform interdomain routing in TCP/IP networks. A BGP router needs to establish a connection (on TCP port 179) to each of it's BGP peers before BGP updates can be exchanged. The BGP session between two BGP peers is said to be an external BGP (eBGP) session if the BGP peers are in different autonomous systems (AS). A BGP session between two BGP peers is said to be an internal BGP (iBGP) session if the BGP peers are in the same AS16509 autonomous system.

By default, the peer relationship is established using the IP address of the interface closest to the peer router. However, using the neighbor update-source command, any operational interface, including the loopback interface, can be specified to be used for establishing TCP connections. This method of peering using a loopback interface is useful since it will not bring down the BGP session when there are multiple paths between the BGP peers, which would otherwise result in tearing down the BGP session if the physical interface used for establishing the session goes down. In addition to that, it also allows the routers running BGP with multiple links between them to load balance over the available paths.

AS16509 Network Diagram

The AS16509 backbone cost burden associated with settlement-free peering traffic exchange should be equitably shared. Regardless of the direction or type of traffic exchanged between the networks, the routing practices and location or interconnection points should be such that each party bears a reasonably equal share of backbone costs.

In the case that the peering party has significant excess inbound traffic volume to deliver to AS16509 (significantly in excess of that being sent outbound by AS16509 to that party) then the parties should agree the routing behaviour expected of one another within reasonable technical, and operationally-feasible bounds.

When the peering partner has network presence in multiple countries or continents where AS16509 also has Points Of Presence, it will be desirable to open peering legs in at least two locations, and maybe more, subject to the cost/benefits of PoP build-out. This is to ensure that the traffic is exchanged optimally in the respective countries/continents and peering interconnections benefit both partners equally.

Peers must be directly connected when using eBGP. If they are not directly connected, the neighbor ebgp-multihop command must be used and a path through an IGP or static route to reach the peer must exist in order for the routers to establish neighbor relationship.

Verify iBGP/eBGP AS16509 Configuration

Use the show ip bgp neighbors command to display information about the TCP and Border Gateway Protocol (BGP) connections and verify if the BGP peer is established. The output of the show ip bgp neighbors command below shows the BGP state as 'Established', which indicates that the BGP peer relationship has been established successfully.

R1-AGS# show ip bgp neighbors | include BGP
BGP neighbor is 10.10.10.2,  remote AS 16509, internal link
  BGP version 4, remote router ID 2.2.2.2
  BGP state = Established, up for 00:04:20
  BGP table version 1, neighbor version 1
R1-AGS#

The show ip bgp neighbors command has been used above with the modifier | include BGP. This makes the output more readable by filtering the the command output and displaying the relevant parts only.

In addition, the show ip bgp summary command can also be used to display the status of all BGP connections, as shown below.

R1-AGS(9)# show ip bgp summary
BGP router identifier 10.1.1.2, local AS number 16509	
BGP table version is 1, main routing table version 1

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
10.10.10.2      4 16509       3       3        1    0    0 00:00:26        0

AS16509 eBGP Configuration with a Loopback Address

You can also configure eBGP/iBGP using a loopback address (or any other operational interface). Loopback interfaces are used in this manner to guarantee reachability in networks with multiple paths as shown in Sample Configurations of the Load Sharing Using the Loopback Address as a BGP Neighbor section of Load Sharing with BGP in Single and Multihomed Environments.

Load balancing with Multihomed AS16509 to Two ISPs Through a Single Local Router

This case shows how to achieve load sharing when multiple links exist between a remote AS and AS16509. These links are terminated in one router at the AS16509 and on multiple routers at remote ASs in a single-homed BGP environment.


ASN IPv4 IPv6 Power
AS1103           1140       224       3  
AS11096           206       0       1  
AS1136           936       174       2  
AS11537           292       0       4  
AS1221           17       0       1  
AS12389           1139       0       2  
AS1239           17       0       3  
AS12552           2       0       1  
AS1257           153       10       3  
AS1273           4222       1214       22  
AS12874           1       0       1  
AS12956           13951       1022       38  
AS1299           149662       30673       923  
AS13030           14852       3720       41  
AS13193           31       0       1  
AS136620           106       0       1  
AS14586           252       0       13  
AS15412           50       457       1  
AS15576           933       0       1  
AS15704           929       0       2  
AS16735           3594       41       14  
AS174           137551       19164       581  
AS1764           0       84       1  
AS18059           3       0       3  
AS1836           4824       1039       11  
AS1853           938       177       2  
AS1916           1233       165       5  
AS197595           38       0       1  
AS198385           2006       498       4  
AS198507           966       193       2  
AS200780           962       0       1  
AS20485           1334       425       8  
AS20562           1887       0       3  
AS20764           2110       534       3  
AS209           1732       59596       539  
AS20965           1050       231       2  
AS2119           532       0       2  
AS21320           299       24       2  
AS22356           1372       0       3  
AS22773           16       0       7  
AS23033           4       0       1  
AS23520           1169       64       3  
AS24115           659       0       1  
AS24130           1       0       1  
AS24724           1036       223       2  
AS24811           1045       0       2  
AS24961           2182       232       6  
AS2497           8755       2901       9  
AS25091           5961       0       5  
AS2516           1303       8       6  
AS25291           7       0       1  
AS2603           1067       31       5  
AS262589           21       0       5  
AS2852           11       0       1  
AS286           3074       795       9  
AS28716           944       0       2  
AS28917           2092       438       4  
AS29075           57       0       2  
AS2914           157094       39594       768  
AS29208           137       0       3  
AS29632           0       669       2  
AS29691           2163       179       5  
AS29791           1       0       1  
AS30781           486       61       5  
AS31133           2081       0       6  
AS31424           1348       426       4  
AS31500           101       0       1  
AS3216           76       0       3  
AS3223           2364       0       4  
AS3257           48494       9036       526  
AS3267           943       0       2  
AS3303           941       0       1  
AS3320           2239       1257       25  
AS3356           55985       5131       368  
AS33891           7236       309       32  
AS34019           1205       193       4  
AS3491           13779       690       66  
AS35280           563       23       9  
AS3549           5064       17       245  
AS37100           695       0       6  
AS37271           1149       279       3  
AS37468           1539       327       5  
AS38001           1439       239       3  
AS39533           2072       446       4  
AS39912           14       6       1  
AS41095           2837       0       7  
AS4134           2       0       2  
AS4230           900       179       4  
AS42525           1155       273       2  
AS42708           1176       100       2  
AS43350           226       0       2  
AS43531           506       145       3  
AS4637           5758       9282       408  
AS46450           54       0       2  
AS47147           5168       1115       4  
AS4755           20389       11588       404  
AS48362           1071       239       2  
AS4844           750       92       2  
AS50304           1976       227       4  
AS50628           0       386       1  
AS50629           2097       669       5  
AS50673           2805       0       6  
AS51945           0       2       1  
AS52320           341       117       6  
AS5511           526       288       281  
AS577           1909       0       5  
AS58299           2013       879       7  
AS58453           2834       8       5  
AS6057           1240       216       5  
AS6327           31       0       1  
AS6453           63468       14450       441  
AS6461           15027       502       33  
AS6661           2       0       1  
AS6724           6       0       2  
AS6730           758       284       1  
AS6762           26322       6238       589  
AS6774           0       4       1  
AS6830           5586       1646       35  
AS6908           30       0       1  
AS6939           30113       66121       174  
AS701           113       63       5  
AS7018           4266       772       10  
AS7473           385       33       4  
AS7575           1286       170       6  
AS7738           921       0       3  
AS7922           70       0       1  
AS8218           7743       2179       11  
AS8220           12596       476       30  
AS8308           7       3       1  
AS8365           0       265       1  
AS8447           113       54       2  
AS8487           966       0       2  
AS852           3732       508       6  
AS8560           132       0       1  
AS8708           4       1       1  
AS8732           23       0       1  
AS8758           2122       531       5  
AS8943           5       22       1  
AS9002           15791       4942       42  
AS9044           236       0       1  
AS9299           1621       518       355  
AS9304           632       0       3  
AS9957           7818       1080       312  
AS14586           252       0       13  
AS14618           58126       1648       490  
AS62785           1055       0       570  
AS7224           271       0       225  
AS8987           4825       4932       464  
AS12350           1096       0       2  
AS12637           956       180       2  
AS12779           3619       921       2  
AS1280           923       0       2  
AS12859           1046       0       2  
AS13237           1156       0       2  
AS13786           61       37       1  
AS1403           1315       116       3  
AS14061           923       0       2  
AS14840           547       41       1  
AS14907           3204       176       4  
AS15435           935       176       2  
AS15547           3168       693       2  
AS15605           944       0       2  
AS16347           965       0       2  
AS17639           1409       92       3  
AS18106           1201       266       2  
AS19151           4140       128       5  
AS198290           965       193       2  
AS199283           1028       219       1  
AS20080           1169       64       3  
AS202032           1887       357       2  
AS20205           1357       136       4  
AS207044           1037       219       2  
AS20811           2112       0       2  
AS20912           944       180       2  
AS20932           1046       228       2  
AS21232           943       177       2  
AS22652           1403       137       3  
AS23106           1231       64       3  
AS24482           19038       3600       5  
AS24875           935       0       2  
AS25160           1039       0       2  
AS25220           1046       228       2  
AS262757           547       41       1  
AS263075           547       41       1  
AS263152           547       41       1  
AS263508           547       0       1  
AS263651           547       41       1  
AS263674           547       41       1  
AS263702           489       5       1  
AS264911           547       0       1  
AS267613           1107       41       2  
AS28186           1096       41       1  
AS28220           547       0       1  
AS28260           546       0       1  
AS28571           0       41       1  
AS28634           1094       0       1  
AS28792           2058       0       2  
AS29140           1035       223       2  
AS29467           1074       250       2  
AS29608           966       193       2  
AS29680           14       0       1  
AS31122           0       228       1  
AS31742           1029       219       2  
AS327960           931       0       2  
AS327983           939       179       2  
AS328137           1862       348       2  
AS328206           0       174       1  
AS328320           931       0       2  
AS328474           939       179       2  
AS3333           935       176       2  
AS34177           1188       193       2  
AS34288           1149       0       2  
AS35266           1029       219       2  
AS35369           912       93       2  
AS37239           940       174       2  
AS37497           1045       0       2  
AS37640           939       174       2  
AS37680           2074       0       2  
AS39122           1196       302       2  
AS397143           1337       126       3  
AS41722           0       172       1  
AS42473           1512       41       2  
AS43578           944       0       2  
AS47692           3108       669       2  
AS49605           2332       570       2  
AS49697           1036       223       2  
AS49709           944       0       2  
AS50300           1039       224       2  
AS50763           935       0       2  
AS50877           1047       228       2  
AS51088           935       176       2  
AS51185           7606       0       4  
AS51873           943       177       2  
AS51907           929       0       2  
AS52720           548       41       1  
AS52863           548       41       1  
AS52873           1098       260       2  
AS53067           547       41       1  
AS53070           547       41       1  
AS5392           944       0       2  
AS553           1035       0       2  
AS56665           2329       13       3  
AS56730           1029       0       2  
AS57111           4716       540       2  
AS57695           2507       434       2  
AS58308           1930       386       2  
AS59414           943       177       2  
AS59605           2245       431       3  
AS59689           965       193       2  
AS59891           943       177       2  
AS61595           547       41       1  
AS63956           838       143       2  
AS64271           547       0       1  
AS64463           943       177       2  
AS6667           1176       0       2  
AS680           1049       177       2  
AS6881           935       175       2  
AS7195           547       41       1  
AS8222           1036       0       2  
AS8283           935       176       2  
AS8426           1225       291       2  
AS8455           935       176       2  
AS8607           1030       0       2  
AS8896           1035       222       2