Reference Guide

202 | Border Gateway Protocol IPv4 (BGPv4)
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Origin
The Origin indicates the origin of the prefix, or how the prefix came into BGP. There are three Origin
codes: IGP, EGP, INCOMPLETE.
• IGP indicated the prefix originated from information learned through an interior gateway protocol.
• EGP indicated the prefix originated from information learned from an EGP protocol, which NGP
replaced.
• INCOMPLETE indicates that the prefix originated from an unknown source.
Generally, an IGP indicator means that the route was derived inside the originating AS. EGP generally
means that a route was learned from an external gateway protocol. An INCOMPLETE origin code
generally results from aggregation, redistribution or other indirect ways of installing routes into BGP.
In FTOS, these origin codes appear as shown in the following example. The question mark (?) indicates an
Origin code of INCOMPLETE. The lower case letter (i) indicates an Origin code of IGP.
FTOS#show ip bgp
BGP table version is 0, local router ID is 10.101.15.13
Status codes: s suppressed, d damped, h history, * valid, > best
Path source: I - internal, a - aggregate, c - confed-external, r - redistributed, n -
network
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 7.0.0.0/29 10.114.8.33 0 0 18508 ?
*> 7.0.0.0/30 10.114.8.33 0 0 18508 ?
*> 9.2.0.0/16 10.114.8.33 10 0 18508 701 i
AS Path
The AS Path is the list of all Autonomous Systems that all the prefixes listed in the update have passed
through. The local AS number is added by the BGP speaker when advertising to a eBGP neighbor.
In FTOS the AS Path is shown in the following example. Note that the Origin attribute is shown following
the AS Path information.
FTOS#show ip bgp paths
Total 30655 Paths
Address Hash Refcount Metric Path
0x4014154 0 3 18508 701 3549 19421 i
0x4013914 0 3 18508 701 7018 14990 i
0x5166d6c 0 3 18508 209 4637 1221 9249 9249 i
0x5e62df4 0 2 18508 701 17302 i
0x3a1814c 0 26 18508 209 22291 i
0x567ea9c 0 75 18508 209 3356 2529 i
0x6cc1294 0 2 18508 209 1239 19265 i
0x6cc18d4 0 1 18508 701 2914 4713 17935 i
0x5982e44 0 162 18508 209 i
0x67d4a14 0 2 18508 701 19878 ?
0x559972c 0 31 18508 209 18756 i
0x59cd3b4 0 2 18508 209 7018 15227 i