#config router bgp
set as 65001Route advertise by Location A to ISP
set router-id 10.109.19.146
config neighbor
edit "10.109.16.172" <----- ISP IP
set soft-reconfiguration enable
set remote-as 1111
next
end
config redistribute "connected"
set status enable
end#Location A # get router info bgp neighbors 10.109.16.172 advertised-routes
BGP table version is 2, local router ID is 10.109.19.146
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight RouteTag PathISP
*> 10.109.16.0/20 10.109.19.146 32768 0 ?
*> 10.201.0.0/20 10.109.19.146 32768 0 ?
*> 10.205.0.0/20 10.109.19.146 32768 0 ?#config router bgpHere ISP is advertising the route to the Location B
set as 1111
config neighbor
edit "10.109.19.146" <----- Location A
set soft-reconfiguration enable
set remote-as 65001
next
edit "10.109.16.73" <----- Location B
set soft-reconfiguration enable
set remote-as 65001
next
end#ISP # get router info bgp neighbors 10.109.16.73 advertised-routesTotal number of prefixes 3
BGP table version is 4, local router ID is 10.201.0.172
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight RouteTag Path
*> 10.109.16.0/20 10.109.19.146 0 0 65001 ?
*> 10.201.0.0/20 10.109.19.146 0 0 65001 ?
*> 10.205.0.0/20 10.109.19.146 0 0 65001 ?
Location Bconfig router bgpThe route advertise is visible by the ISP, but route is not installed in the routing table of location B.
set as 65001
config neighbor
edit "10.109.16.172" <----- ISP
set soft-reconfiguration enable
set remote-as 1111
next
end#Location B # get router info bgp neighbors 10.109.16.172 received-route
BGP table version is 1, local router ID is 192.168.100.99
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight RouteTag PathTotal number of prefixes 3
*> 10.109.16.0/20 10.109.19.146 0 0 1111 65001 ?
*> 10.201.0.0/20 10.109.19.146 0 0 1111 65001 ?
*> 10.205.0.0/20 10.109.19.146 0 0 1111 65001
In routing table of location B route is not installed#Location B # get router info routing-table detailsRouting table for VRF=0
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate defaultS* 0.0.0.0/0 [10/0] via 10.109.31.254, port1SOLUTION:
[10/0] via 10.109.63.254, mgmt
C 10.109.16.0/20 is directly connected, port1
There are two solutions to overcome this problem:
1) Configure the 'allowas-in-enable' in the bgp config of Location B.
Location B##config router bgp
set as 65001
config neighbor
edit "10.109.16.172" <----- ISP
set allowas-in-enable enable
set soft-reconfiguration enable
set remote-as 1111
next
end#Location B # get router info routing-table details2) Enable the 'as-override' in the bgp config of ISP.
Routing table for VRF=0
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default
S* 0.0.0.0/0 [10/0] via 10.109.31.254, port1
[10/0] via 10.109.63.254, mgmt
C 10.109.16.0/20 is directly connected, port1
B 10.201.0.0/20 [20/0] via 10.109.19.146, port1, 00:00:38
B 10.205.0.0/20 [20/0] via 10.109.19.146, port1, 00:00:38
#Location B # get router info bgp network 10.205.0.0/20
BGP routing table entry for 10.205.0.0/20
Paths: (1 available, best #1, table Default-IP-Routing-Table)
Not advertised to any peer
1111 65001
10.109.19.146 from 10.109.16.172 (10.201.0.172)
Origin incomplete metric 0, localpref 100, valid, external, best
Last update: Sun Oct 6 13:13:19 2019
ISP##config router bgpAfter enabling the as-override, the routes are available in the routing table of Location B
set as 1111
config neighbor
edit "10.109.19.146"
set soft-reconfiguration enable
set as-override enable
set remote-as 65001
next
edit "10.109.16.73"
set soft-reconfiguration enable
set as-override enable
set remote-as 65001
next
end#Location B # get router info routing-table detailsNote: After enabling the 'allowas-in-enable' or 'as-override' bgp neighbor gets down and came up.
Routing table for VRF=0
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default
S* 0.0.0.0/0 [10/0] via 10.109.31.254, port1
C 10.109.16.0/20 is directly connected, port1
B 10.201.0.0/20 [20/0] via 10.109.19.146, port1, 00:02:23
B 10.205.0.0/20 [20/0] via 10.109.19.146, port1, 00:02:23
#Location B # get router info bgp network 10.201.0.0/20
BGP routing table entry for 10.201.0.0/20
Paths: (1 available, best #1, table Default-IP-Routing-Table)
Not advertised to any peer
1111 1111
10.109.19.146 from 10.109.16.172 (10.201.0.172)
Origin incomplete metric 0, localpref 100, valid, external, best
Last update: Sun Oct 6 14:25:57 2019
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