Configuration ------------------ Router A ------------ ip route 0.0.0.0/0 enp0s8 ip route 85.1.1.0/24 enp0s8 ! router bgp 1 neighbor 192.168.0.116 remote-as 2 neighbor 192.168.0.117 remote-as 3 ! access-list ip seq 5 permit 86.1.1.0/24 ! route-map rmap permit 1 match ip address ip Router B ------------ router bgp 2 neighbor 192.168.0.118 remote-as 1 Router C ------------ router bgp 3 neighbor 192.168.0.118 remote-as 1 ====================================================================================== 1) Configure default static route and redistribute static and verify default route is advertised LOGS --------- Router A ------------ linux(config-router)# address-family ipv4 unicast linux(config-router-af)# redistribute static show ip bgp BGP table version is 12, local router ID is 192.168.0.118, vrf id 0 Default local pref 100, local AS 1 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 0.0.0.0/0 0.0.0.0 0 32768 ? *> 85.1.1.0/24 0.0.0.0 0 32768 ? Router B ------------ linux# show ip bgp BGP table version is 21, local router ID is 192.168.0.117, vrf id 0 Default local pref 100, local AS 2 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 0.0.0.0/0 192.168.0.118 0 0 1 ? *> 85.1.1.0/24 192.168.0.118 0 0 1 ? Displayed 2 routes and 2 total paths linux# show ip bgp 0.0.0.0/0 BGP routing table entry for 0.0.0.0/0 Paths: (1 available, best #1, table default) Advertised to non peer-group peers: 192.168.0.118 1 192.168.0.118 from 192.168.0.118 (192.168.0.118) Origin incomplete, metric 0, valid, external, best (First path received) Last update: Fri Apr 10 14:18:31 2020 Router C ------------ linux# show ip bgp BGP table version is 21, local router ID is 192.168.0.116, vrf id 0 Default local pref 100, local AS 3 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 0.0.0.0/0 192.168.0.118 0 0 1 ? *> 85.1.1.0/24 192.168.0.118 0 0 1 ? Displayed 2 routes and 2 total paths linux# show ip bgp 0.0.0.0/0 BGP routing table entry for 0.0.0.0/0 Paths: (1 available, best #1, table default) Advertised to non peer-group peers: 192.168.0.118 1 192.168.0.118 from 192.168.0.118 (192.168.0.118) Origin incomplete, metric 0, valid, external, best (First path received) Last update: Fri Apr 10 14:18:30 2020 The default route in peers is having the origin INCOMPLETE (redistribute command) as expected ========================================================================================================== 2) Configure default originate for peers and verify is default route is present in the peers Router A ------------ linux(config-router-af)# neighbor 192.168.0.116 default-originate linux(config-router-af)# neighbor 192.168.0.117 default-originate Router B ------------ linux# show ip bgp 0.0.0.0/0 BGP routing table entry for 0.0.0.0/0 Paths: (1 available, best #1, table default) Advertised to non peer-group peers: 192.168.0.118 1 192.168.0.118 from 192.168.0.118 (192.168.0.118) Origin IGP, valid, external, best (First path received) <====================== Last update: Fri Apr 10 14:23:11 2020 Router C ------------ linux# show ip bgp 0.0.0.0/0 BGP routing table entry for 0.0.0.0/0 Paths: (1 available, best #1, table default) Advertised to non peer-group peers: 192.168.0.118 1 192.168.0.118 from 192.168.0.118 (192.168.0.118) Origin IGP, valid, external, best (First path received) <====================== Last update: Fri Apr 10 14:23:07 2020 The default route gets updated in the peers with origin IGP (default originate command) as expected ====================================================================================================== 3) Configure default originate with routemap or peers and verify is default route is present in the peers Router A ------------ router bgp 1 neighbor 192.168.0.116 remote-as 3 neighbor 192.168.0.117 remote-as 2 ! address-family ipv4 unicast redistribute static neighbor 192.168.0.116 default-originate route-map rmap <==================== neighbor 192.168.0.117 default-originate route-map rmap <==================== exit-address-family ! access-list ip seq 5 permit 86.1.1.0/24 ! route-map rmap permit 1 match ip address ip Router B ------------ linux# show ip bgp BGP table version is 25, local router ID is 192.168.0.117, vrf id 0 Default local pref 100, local AS 2 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 85.1.1.0/24 192.168.0.118 0 0 1 ? Displayed 1 routes and 1 total paths linux# show ip bgp 0.0.0.0/0 % Network not in table <==================== Router C ------------ linux# show ip bgp BGP table version is 25, local router ID is 192.168.0.116, vrf id 0 Default local pref 100, local AS 3 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 85.1.1.0/24 192.168.0.118 0 0 1 ? Displayed 1 routes and 1 total paths linux# linux# show ip bgp 0.0.0.0/0 % Network not in table <==================== The routemap does not match for default originate since 86.1.1.0/24 is not in BGP RIB. Therefore this is treated as withdraw and the default route is withdrawn. The default originate configuration is still present for peers, therefore the static default route is not advertised. =================================================================================================== 4) Modify the access list to include matching routes in the BGP RIB Router A ------------ access-list ip seq 10 permit 85.1.1.0/24 <================ access-list ip seq 5 permit 86.1.1.0/24 Router B ------------ linux# show ip bgp BGP table version is 30, local router ID is 192.168.0.117, vrf id 0 Default local pref 100, local AS 2 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 0.0.0.0/0 192.168.0.118 0 1 i *> 85.1.1.0/24 192.168.0.118 0 0 1 ? Displayed 2 routes and 2 total paths linux# show ip bgp 0.0.0.0/0 BGP routing table entry for 0.0.0.0/0 Paths: (1 available, best #1, table default) Advertised to non peer-group peers: 192.168.0.118 1 192.168.0.118 from 192.168.0.118 (192.168.0.118) Origin IGP, valid, external, best (First path received) <========================= Last update: Fri Apr 10 14:29:15 2020 Router C ------------ linux# show ip bgp BGP table version is 30, local router ID is 192.168.0.117, vrf id 0 Default local pref 100, local AS 2 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 0.0.0.0/0 192.168.0.118 0 1 i *> 85.1.1.0/24 192.168.0.118 0 0 1 ? Displayed 2 routes and 2 total paths linux# show ip bgp 0.0.0.0/0 BGP routing table entry for 0.0.0.0/0 Paths: (1 available, best #1, table default) Advertised to non peer-group peers: 192.168.0.118 1 192.168.0.118 from 192.168.0.118 (192.168.0.118) Origin IGP, valid, external, best (First path received) <========================= Last update: Fri Apr 10 14:29:15 2020 The default routes gets advertised with origin IGP (default originate command) as expected. ================================================================================================== 5) Remove the default originate command and verify that if there is a default route in RIB, the route gets advertised to peers Router A ------------ linux(config)# router bgp 1 linux(config-router)# address-family ipv4 unicast linux(config-router-af)# no neighbor 192.168.0.116 default-originate route-map rmap linux(config-router-af)# no neighbor 192.168.0.117 default-originate route-map rmap router bgp 1 neighbor 192.168.0.116 remote-as 3 neighbor 192.168.0.117 remote-as 2 ! address-family ipv4 unicast redistribute static exit-address-family ! access-list ip seq 10 permit 85.1.1.0/24 access-list ip seq 5 permit 86.1.1.0/24 ! route-map rmap permit 1 match ip address ip Router B ------------ linux# show ip bgp BGP table version is 31, local router ID is 192.168.0.117, vrf id 0 Default local pref 100, local AS 2 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 0.0.0.0/0 192.168.0.118 0 0 1 ? *> 85.1.1.0/24 192.168.0.118 0 0 1 ? Displayed 2 routes and 2 total paths linux# show ip bgp 0.0.0.0/0 BGP routing table entry for 0.0.0.0/0 Paths: (1 available, best #1, table default) Advertised to non peer-group peers: 192.168.0.118 1 192.168.0.118 from 192.168.0.118 (192.168.0.118) Origin incomplete, metric 0, valid, external, best (First path received) <======================= Last update: Fri Apr 10 14:38:53 2020 Router C ------------ linux# show ip bgp BGP table version is 31, local router ID is 192.168.0.116, vrf id 0 Default local pref 100, local AS 3 Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 0.0.0.0/0 192.168.0.118 0 0 1 ? *> 85.1.1.0/24 192.168.0.118 0 0 1 ? Displayed 2 routes and 2 total paths linux# show ip bgp 0.0.0.0/0 BGP routing table entry for 0.0.0.0/0 Paths: (1 available, best #1, table default) Advertised to non peer-group peers: 192.168.0.118 1 192.168.0.118 from 192.168.0.118 (192.168.0.118) Origin incomplete, metric 0, valid, external, best (First path received) <======================= Last update: Fri Apr 10 14:38:49 2020 The peers receive the default route with the origin INCOMPLETE (redistribte command) as expected