Default-Originate

This scenario demonstrates how to configure a BGP neighbor to advertise a default route using the default-originate command. Tests include unconditional advertisement and conditional advertisement using a route-map to control when the default route is sent.

Test iBGP - Neighbor default-originate

Description

Test to verify that the default-originate command unconditionally advertises a default route (0.0.0.0/0) to the BGP neighbor.

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces ethernet eth0 address 10.10.0.100/24
set protocols bgp 20 neighbor peer default-originate
set protocols bgp 20 neighbor peer remote-address 10.10.0.200
set protocols bgp 20 neighbor peer remote-as 20
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Set the following configuration in DUT1 :

set interfaces ethernet eth0 address 10.10.0.200/24
set protocols bgp 20 neighbor peer remote-address 10.10.0.100
set protocols bgp 20 neighbor peer remote-as 20
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 3: Run the command protocols bgp show ip summary on DUT0 and check whether the output contains the following tokens:

Established
Show output
IPv4 Unicast Summary:
BGP router identifier 10.10.0.100, local AS number 20 VRF default vrf-id 0
BGP table version 0
RIB entries 0, using 0 bytes of memory
Peers 1, using 24 KiB of memory

Neighbor        LocalAddr       V         AS   MsgRcvd   MsgSent   TblVer  InQ OutQ  Up/Down        State   PfxRcd   PfxSnt Desc
10.10.0.200     10.10.0.100     4         20         3         5        0    0    0 00:00:05  Established        0        1 N/A

Total number of neighbors 1

Attention

Verify iBGP session establishes.

Step 4: Run the command protocols bgp show ip summary on DUT0 and check whether the output matches the following regular expressions:

10.10.0.200.*Established
Show output
IPv4 Unicast Summary:
BGP router identifier 10.10.0.100, local AS number 20 VRF default vrf-id 0
BGP table version 0
RIB entries 0, using 0 bytes of memory
Peers 1, using 24 KiB of memory

Neighbor        LocalAddr       V         AS   MsgRcvd   MsgSent   TblVer  InQ OutQ  Up/Down        State   PfxRcd   PfxSnt Desc
10.10.0.200     10.10.0.100     4         20         3         5        0    0    0 00:00:05  Established        0        1 N/A

Total number of neighbors 1

Attention

Verify that DUT1 receives the default route 0.0.0.0/0 from DUT0.

Step 5: Run the command protocols bgp show ip 0.0.0.0/0 on DUT1 and check whether the output contains the following tokens:

10.10.0.100 from 10.10.0.100 (10.10.0.100)
Show output
BGP routing table entry for 0.0.0.0/0, version 1
Paths: (1 available, best #1, table default)
  Not advertised to any peer
  Local
    10.10.0.100 from 10.10.0.100 (10.10.0.100)
      Origin IGP, metric 0, localpref 100, valid, internal, best (First path received)
      Last update: Tue May 19 14:40:27 2026

Test iBGP - Neighbor default-originate with route-map

Description

Test to verify that the default-originate command with route-map conditionally advertises a default route (0.0.0.0/0) to the BGP neighbor. DUT0 originates default route only when route 1.1.1.0/24 exists (matched by route-map).

Scenario

Step 1: Set the following configuration in DUT0 :

set interfaces dummy dum0 address 1.1.1.1/24
set interfaces ethernet eth0 address 10.10.0.100/24
set protocols bgp 20 neighbor peer default-originate route-map DEFAULT-MAP
set protocols bgp 20 neighbor peer remote-address 10.10.0.200
set protocols bgp 20 neighbor peer remote-as 20
set protocols bgp 20 redistribute connected
set protocols ip prefix-list TRACK rule 10 action permit
set protocols ip prefix-list TRACK rule 10 prefix 1.1.1.0/24
set protocols route-map DEFAULT-MAP rule 10 action permit
set protocols route-map DEFAULT-MAP rule 10 match ip address prefix-list TRACK
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 2: Set the following configuration in DUT1 :

set interfaces ethernet eth0 address 10.10.0.200/24
set protocols bgp 20 neighbor peer remote-address 10.10.0.100
set protocols bgp 20 neighbor peer remote-as 20
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Step 3: Run the command protocols bgp show ip summary on DUT0 and check whether the output contains the following tokens:

Established
Show output
IPv4 Unicast Summary:
BGP router identifier 10.10.0.100, local AS number 20 VRF default vrf-id 0
BGP table version 3
RIB entries 3, using 456 bytes of memory
Peers 1, using 24 KiB of memory

Neighbor        LocalAddr       V         AS   MsgRcvd   MsgSent   TblVer  InQ OutQ  Up/Down        State   PfxRcd   PfxSnt Desc
10.10.0.200     10.10.0.100     4         20         3         8        3    0    0 00:00:04  Established        0        3 N/A

Total number of neighbors 1

Attention

Verify iBGP session establishes.

Step 4: Run the command protocols bgp show ip summary on DUT0 and check whether the output matches the following regular expressions:

10.10.0.200.*Established
Show output
IPv4 Unicast Summary:
BGP router identifier 10.10.0.100, local AS number 20 VRF default vrf-id 0
BGP table version 3
RIB entries 3, using 456 bytes of memory
Peers 1, using 24 KiB of memory

Neighbor        LocalAddr       V         AS   MsgRcvd   MsgSent   TblVer  InQ OutQ  Up/Down        State   PfxRcd   PfxSnt Desc
10.10.0.200     10.10.0.100     4         20         3         8        3    0    0 00:00:04  Established        0        3 N/A

Total number of neighbors 1

Attention

Verify that DUT1 receives the default route 0.0.0.0/0 from DUT0.

Step 5: Run the command protocols bgp show ip 0.0.0.0/0 on DUT1 and check whether the output contains the following tokens:

10.10.0.100 from 10.10.0.100 (10.10.0.100)
Show output
BGP routing table entry for 0.0.0.0/0, version 1
Paths: (1 available, best #1, table default)
  Not advertised to any peer
  Local
    10.10.0.100 from 10.10.0.100 (10.10.0.100)
      Origin IGP, metric 0, localpref 100, valid, internal, best (First path received)
      Last update: Tue May 19 14:40:41 2026