AS293 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.

AS293 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 AS293 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.

AS293 Network Diagram

The AS293 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 AS293 (significantly in excess of that being sent outbound by AS293 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 AS293 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 AS293 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 293, 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 293	
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      4 293       3       3        1    0    0 00:00:26        0

AS293 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 AS293 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 AS293. These links are terminated in one router at the AS293 and on multiple routers at remote ASs in a single-homed BGP environment.


ASN IPv4 IPv6 Power
AS1103           316       46       62  
AS11537           29       0       6  
AS12956           141       69       51  
AS16735           319       69       84  
AS20965           316       46       62  
AS2497           477       70       32  
AS2914           4132       661       625  
AS3320           1092       0       222  
AS3356           741       154       243  
AS3491           732       23       141  
AS6453           1440       246       218  
AS6939           46239       6412       6960  
AS7575           137       23       30  
AS8359           124       0       25  
AS9002           1299       232       241  
AS101           213       0       41  
AS103           22       0       1  
AS10490           228       0       51  
AS10578           547       0       81  
AS10702           694       360       315  
AS10764           1       0       1  
AS10886           169       0       33  
AS11096           248       0       45  
AS11317           570       0       57  
AS11404           1347       0       267  
AS11537           1575       0       285  
AS11678           386       365       323  
AS1224           2       0       1  
AS14041           157       0       33  
AS14877           222       0       50  
AS16           778       359       323  
AS160           5       0       1  
AS16411           1544       359       320  
AS16905           219       0       45  
AS17579           12       0       3  
AS195           35       0       5  
AS19782           136       0       25  
AS2153           1030       0       137  
AS22335           217       0       41  
AS226           189       0       19  
AS237           135       0       30  
AS2381           161       0       26  
AS24           4       0       2  
AS2640           385       345       315  
AS291           3468       0       279  
AS292           774       0       281  
AS2936           389       359       323  
AS297           1       0       1  
AS3           78       0       2  
AS3152           1547       360       325  
AS32982           7583       0       251  
AS3380           1543       0       276  
AS3424           74       359       247  
AS3425           386       0       274  
AS3428           1596       359       309  
AS3431           1540       0       272  
AS3443           386       0       273  
AS3562           2708       360       322  
AS36692           38       0       2  
AS3671           759       360       325  
AS3676           35       0       11  
AS3754           204       0       48  
AS377           2712       359       321  
AS3999           12       0       1  
AS40387           10       0       5  
AS40498           94       0       14  
AS43           1929       1079       324  
AS44           2325       0       281  
AS45           4260       0       278  
AS46846           346       0       241  
AS50           3844       360       321  
AS5050           39       0       11  
AS5078           83       0       20  
AS513           29       0       6  
AS54297           382       359       510  
AS59           8       0       1  
AS63331           1155       356       320  
AS6406           775       346       319  
AS668           283       0       23  
AS68           3100       360       329  
AS683           9778       345       319  
AS7575           513       0       90  
AS88           2       0       1  
AS11708           157       0       30  
AS1273           0       23       20  
AS18106           157       22       31  
AS19151           318       45       31  
AS24482           314       44       31  
AS32097           157       0       30  
AS46997           157       22       31  
AS513           9003       23       1541  
AS64271           157       0       30