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           1312       236       3  
AS11096           62       0       1  
AS11537           51       282       5  
AS1221           10000       15601       514  
AS12389           164       21       2  
AS1239           413       24       6  
AS1257           153       20       3  
AS1267           1337       0       2  
AS1273           2313       1688       22  
AS12874           1       0       1  
AS12956           11647       3094       20  
AS1299           199262       79947       1237  
AS13030           25589       5544       73  
AS13193           44       0       1  
AS133530           332       0       268  
AS13786           1748       220       7  
AS15412           284       0       2  
AS15576           2       188       2  
AS15623           1129       191       2  
AS15704           449       0       1  
AS15830           148       11       1  
AS16735           2783       494       13  
AS174           234454       58095       955  
AS1764           0       92       1  
AS18059           7       0       7  
AS1820           169       0       1  
AS1836           1664       1043       6  
AS1853           1129       192       2  
AS1916           1632       334       5  
AS198385           2338       470       4  
AS198507           1       0       1  
AS199714           0       3       1  
AS20485           1447       380       6  
AS205112           0       193       2  
AS20562           2469       0       5  
AS20764           2522       584       3  
AS20766           126       1       2  
AS209           193       18       14  
AS20965           1244       242       2  
AS2119           1357       0       2  
AS21320           298       140       2  
AS2153           18       0       3  
AS22773           91       0       13  
AS23033           1024       0       4  
AS23520           1567       151       3  
AS24482           43213       9863       16  
AS24724           1231       49       2  
AS24811           1249       0       2  
AS24961           2363       817       9  
AS2497           10233       3669       12  
AS25091           7103       0       8  
AS2516           1475       4       6  
AS25512           1       0       1  
AS2603           1332       56       8  
AS27281           13       54       34  
AS28329           1       0       1  
AS2852           12       0       1  
AS286           1442       406       6  
AS28716           1138       0       2  
AS29075           1205       0       6  
AS2914           172315       92463       874  
AS29208           147       0       16  
AS29632           0       780       4  
AS29691           3383       573       6  
AS29695           0       146       2  
AS30517           9       0       7  
AS30781           652       405       6  
AS31133           2514       401       5  
AS3216           1449       76       6  
AS3257           62828       12527       592  
AS3267           1154       0       2  
AS328145           1210       295       3  
AS3303           4525       577       7  
AS3320           17799       2807       133  
AS3356           37907       9654       300  
AS33891           7562       1829       49  
AS34019           6389       1300       4  
AS34549           6170       1849       20  
AS34854           2466       472       4  
AS3491           14237       4541       195  
AS34927           3611       667       3  
AS35189           1152       0       2  
AS35280           11815       3263       39  
AS35320           1       0       1  
AS3549           42       0       35  
AS35625           12       0       1  
AS37100           916       0       8  
AS37271           1413       283       3  
AS3741           16       0       1  
AS37468           2137       319       8  
AS37662           1231       0       2  
AS39533           10877       2243       23  
AS39912           10       6       1  
AS40317           3       0       3  
AS40511           1       0       1  
AS41095           3136       118       6  
AS41327           4585       2163       11  
AS4134           2420       0       35  
AS4230           12       9       2  
AS42708           1363       186       2  
AS43531           889       456       6  
AS4637           863       60       7  
AS4657           77       0       2  
AS4755           20735       13120       724  
AS4766           0       2941       122  
AS4788           0       4       1  
AS4826           1602       0       5  
AS48362           6261       896       6  
AS4844           969       157       2  
AS49832           1       0       1  
AS50304           2463       437       7  
AS50629           4977       853       12  
AS50673           2277       0       4  
AS50903           7       0       1  
AS52320           2997       224       10  
AS52468           3       1       2  
AS53340           509       0       5  
AS5511           3437       321       102  
AS56655           0       200       2  
AS5713           2       0       1  
AS58299           2572       670       9  
AS58453           107       2       3  
AS6057           1639       378       5  
AS62240           1       0       1  
AS6453           54501       23278       492  
AS6461           23509       4001       52  
AS6661           1       0       1  
AS6730           1342       38       2  
AS6762           53421       9951       644  
AS6805           24       0       1  
AS6830           14213       2200       45  
AS6908           9803       1884       4  
AS6939           26205       15122       194  
AS701           121       0       4  
AS7018           3458       468       8  
AS7195           1669       203       7  
AS7224           15768       0       4  
AS7473           3       5       4  
AS7545           0       20       1  
AS7575           1556       254       6  
AS7738           1069       0       3  
AS7922           20       0       2  
AS8218           10223       2617       10  
AS8220           8544       97       24  
AS8308           11       27       1  
AS8359           2497       75       10  
AS8365           0       275       1  
AS8374           0       163       1  
AS8447           116       50       2  
AS852           6359       572       10  
AS8529           0       1722       161  
AS8560           130       0       1  
AS8708           1362       3       3  
AS8732           22       0       1  
AS8758           4598       511       5  
AS8943           77       38       1  
AS9002           33253       8333       48  
AS9044           208       0       1  
AS9299           2351       676       511  
AS9304           711       0       3  
AS9957           11858       1071       451  
AS14618           112840       6177       584  
AS62785           2297       0       642  
AS7224           661       0       430  
AS8987           7249       6538       466  
AS12350           1262       0       2  
AS12637           1160       197       2  
AS12779           4146       1232       2  
AS1280           1076       0       3  
AS12859           1250       0       2  
AS13237           1343       0       2  
AS137409           969       157       2  
AS1403           1566       300       3  
AS14061           4875       685       4  
AS14840           604       36       1  
AS14907           3187       489       4  
AS15435           1140       197       2  
AS15547           3726       573       2  
AS15605           1254       236       2  
AS16347           1153       0       2  
AS17639           1567       0       3  
AS18106           3188       620       5  
AS19151           4801       838       5  
AS198290           1152       205       2  
AS199283           1209       228       1  
AS199524           8486       1167       5  
AS199938           1159       209       2  
AS20080           1567       151       3  
AS202032           2269       388       2  
AS20205           1603       168       3  
AS204708           1156       206       2  
AS205344           1154       205       2  
AS207044           1218       232       2  
AS20811           2508       394       2  
AS20912           1140       197       2  
AS20932           1250       244       2  
AS21232           1129       191       2  
AS22548           604       0       1  
AS22652           1566       150       3  
AS23106           1210       368       3  
AS24875           1138       0       2  
AS25160           1226       0       2  
AS25220           1250       244       2  
AS26073           1072       135       2  
AS263075           604       36       1  
AS263152           604       36       1  
AS263508           604       36       1  
AS263651           604       36       1  
AS263702           545       6       1  
AS264911           604       36       1  
AS267613           605       36       2  
AS28186           1208       36       1  
AS28571           0       34       1  
AS28634           2414       0       2  
AS28792           2420       0       2  
AS28917           1248       488       2  
AS29140           1233       236       2  
AS29467           1261       260       2  
AS29608           1153       205       2  
AS31122           0       240       1  
AS31424           1176       0       2  
AS31742           1210       228       2  
AS327781           1107       0       2  
AS327960           1107       0       2  
AS327983           1119       171       2  
AS328137           2214       342       2  
AS328206           0       171       1  
AS328320           1107       0       2  
AS328474           1120       0       2  
AS3333           1140       197       2  
AS34177           1364       205       2  
AS34288           1336       0       2  
AS35266           1208       228       2  
AS35369           1100       100       2  
AS36924           1166       213       2  
AS37239           1120       171       2  
AS37497           1226       0       2  
AS37640           1120       171       2  
AS37680           2422       0       2  
AS37721           3597       425       2  
AS38001           0       245       1  
AS39122           1372       303       2  
AS39351           1406       323       2  
AS393950           1567       0       3  
AS397143           1579       151       3  
AS41157           1152       205       2  
AS41722           1119       174       2  
AS42473           599       34       1  
AS42541           1156       205       2  
AS42861           1121       522       2  
AS43578           1142       0       2  
AS45896           706       0       2  
AS47147           4928       944       2  
AS47692           3732       726       2  
AS49434           1148       0       1  
AS49605           2706       582       2  
AS49697           1234       236       2  
AS49709           1140       197       2  
AS50300           1226       236       2  
AS50628           2304       410       2  
AS50763           1140       197       2  
AS50877           1228       237       2  
AS51088           1140       197       2  
AS51184           3756       738       2  
AS51185           9212       939       4  
AS51873           1129       191       2  
AS51907           1121       0       2  
AS52720           604       36       1  
AS52863           605       36       1  
AS52873           605       36       2  
AS53067           604       36       1  
AS53070           604       36       1  
AS5392           1138       0       2  
AS553           1227       234       2  
AS55720           791       0       2  
AS5602           1138       0       2  
AS56665           2901       314       3  
AS57111           1138       197       2  
AS57695           5295       871       2  
AS58308           2326       418       2  
AS58952           969       157       2  
AS59414           1129       191       2  
AS59605           2792       543       3  
AS59689           1152       205       2  
AS59891           1130       191       2  
AS60501           2112       0       2  
AS60945           1210       228       2  
AS61595           599       34       1  
AS61597           0       36       1  
AS62167           2468       480       2  
AS6233           604       36       1  
AS63956           1011       181       2  
AS64271           708       83       3  
AS64475           1234       236       2  
AS6667           1374       348       2  
AS680           1247       196       2  
AS6881           1141       193       2  
AS8283           1140       197       2  
AS8455           1140       197       2  
AS8607           1211       0       2  
AS8896           1216       231       2