In an MPLS L3VPN scenario, why doesn't an IBGP peer advertise routes to the other IBGP peers?

Hi,
We've noticed about your problem, and we're processing on.

Hi

could you send the vpns settings in the other iBGP PE please?

Huawei by default exports the routes known by eBGP to iBGP peers.

The only thing that could be happening is that the peer in vpnv4 is not declared within the MP-BGP family of your router.

Could you also submit the BGP config?

<PE2>display bgp vpnv4 all peer 1.1.1.1 verbose



BGP Peer is 1.1.1.1, remote AS 100

Type: IBGP link

BGP version 4, Remote router ID 10.10.10.1

Update-group ID: 1

BGP current state: Established, Up for 00h01m53s

BGP current event: KATimerExpired

BGP last state: OpenConfirm

BGP Peer Up count: 1

Received total routes: 2

Received active routes total: 2

Advertised total routes: 2

Port: Local - 50938 Remote - 179

Configured: Connect-retry Time: 32 sec

Configured: Active Hold Time: 180 sec Keepalive Time:60 sec

Received : Active Hold Time: 180 sec

Negotiated: Active Hold Time: 180 sec Keepalive Time:60 sec

Peer optional capabilities:

Peer supports bgp multi-protocol extension

Peer supports bgp route refresh capability

Peer supports bgp 4-byte-as capability

Address family IPv4 Unicast: advertised and received

Address family VPNv4: advertised and received

Received: Total 6 messages

Update messages 3

Open messages 1

KeepAlive messages 2

Notification messages 0

Refresh messages 0

Sent: Total 4 messages

Update messages 1

Open messages 1

KeepAlive messages 2

Notification messages 0

Refresh messages 0

Authentication type configured: None

Last keepalive received: 2021/06/15 01:32:03 UTC-08:00

Last keepalive sent : 2021/06/15 01:32:03 UTC-08:00

Last update received: 2021/06/15 01:31:11 UTC-08:00

Last update sent : 2021/06/15 01:31:03 UTC-08:00

Minimum route advertisement interval is 0 seconds

Optional capabilities:

Route refresh capability has been enabled

4-byte-as capability has been enabled

Connect-interface has been configured

Peer Preferred Value: 0

Routing policy configured:

No routing policy is configured

<PE2>



<PE3>display bgp vpnv4 all peer 1.1.1.1 verbose



BGP Peer is 1.1.1.1, remote AS 100

Type: IBGP link

BGP version 4, Remote router ID 10.10.10.1

Update-group ID: 1

BGP current state: Established, Up for 00h05m14s

BGP current event: KATimerExpired

BGP last state: OpenConfirm

BGP Peer Up count: 1

Received total routes: 1

Received active routes total: 1

Advertised total routes: 0

Port: Local - 49873 Remote - 179

Configured: Connect-retry Time: 32 sec

Configured: Active Hold Time: 180 sec Keepalive Time:60 sec

Received : Active Hold Time: 180 sec

Negotiated: Active Hold Time: 180 sec Keepalive Time:60 sec

Peer optional capabilities:

Peer supports bgp multi-protocol extension

Peer supports bgp route refresh capability

Peer supports bgp 4-byte-as capability

Address family IPv4 Unicast: advertised and received

Address family VPNv4: advertised and received

Received: Total 10 messages

Update messages 3

Open messages 1

KeepAlive messages 6

Notification messages 0

Refresh messages 0

Sent: Total 7 messages

Update messages 0

Open messages 1

KeepAlive messages 6

Notification messages 0

Refresh messages 0

Authentication type configured: None

Last keepalive received: 2021/06/15 01:35:33 UTC-08:00

Last keepalive sent : 2021/06/15 01:35:35 UTC-08:00

Last update received: 2021/06/15 01:31:11 UTC-08:00

Minimum route advertisement interval is 0 seconds

Optional capabilities:

Route refresh capability has been enabled

4-byte-as capability has been enabled

Connect-interface has been configured

Peer Preferred Value: 0

Routing policy configured:

No routing policy is configured

<PE3>



<PE2>disp bgp vpnv4 vpn-instance vpna routing-table peer 1.1.1.1 received-routes



Info: The peer does not exist.



<PE3>disp bgp vpnv4 vpn-instance vpnb routing-table peer 1.1.1.1 received-routes



Info: The peer does not exist.

The correct import of the routes corresponding to each vpn-instance is shown in PE1

PE2

PE3

- Connectivity test from PC2 to PC1

- Configuring vpn-instance PE1

ip vpn-instance CLIENTE_A

 ipv4-family

  route-distinguisher 1:200

  vpn-target 1:200 export-extcommunity

  vpn-target 200:1 import-extcommunity

#

ip vpn-instance CLIENTE_B

 ipv4-family

  route-distinguisher 1:300

  vpn-target 1:300 export-extcommunity

  vpn-target 300:1 import-extcommunity

#

- Pe1 ip address configuration

GigabitEthernet0/0/2 interface

 ip binding vpn-instance CLIENTE_A

 ip address 20.20.10.1 255.255.255.0 

#

GigabitEthernet2/0/0 interface

 ip binding vpn-instance CLIENTE_B

 ip address 20.20.20.1 255.255.255.0 

#

- configuring BGP in PE1

bgp 100

 router-id 1.1.1.1

 peer 6.6.6.6 as-number 100 

 peer 6.6.6.6 connect-interface LoopBack0

 peer 7.7.7.7 as-number 100 

 peer 7.7.7.7 connect-interface LoopBack0

 #

 ipv4-family unicast

  undo synchronization

  peer 6.6.6.6 enable

  peer 7.7.7.7 enable

 # 

 ipv4-family vpnv4

  policy vpn-target

  peer 6.6.6.6 enable

  peer 7.7.7.7 enable

 #

 ipv4-family vpn-instance CLIENTE_A 

  import-route direct

  peer 20.20.10.2 as-number 200 

 #

 ipv4-family vpn-instance CLIENTE_B 

  import-route direct

  peer 20.20.20.2 as-number 300 

#

- Configuring vpn-instance PE2

ip vpn-instance CLIENTE_A

 ipv4-family

  route-distinguisher 1:200

  vpn-target 200:1 export-extcommunity

  vpn-target 1:200 import-extcommunity

#

- Pe2 ip address configuration

GigabitEthernet0/0/2 interface

 ip binding vpn-instance CLIENTE_A

 ip address 20.20.30.1 255.255.255.0 

#

- BGP configuration in PE2

bgp 100

 router-id 6.6.6.6

 peer 1.1.1.1 as-number 100 

 peer 1.1.1.1 connect-interface LoopBack0

 #

 ipv4-family unicast

  undo synchronization

  peer 1.1.1.1 enable

 # 

 ipv4-family vpnv4

  policy vpn-target

  peer 1.1.1.1 enable

 #

 ipv4-family vpn-instance CLIENTE_A 

  import-route direct

  peer 20.20.30.2 as-number 400 

#

- Configuration of vpn-instance PE3

ip vpn-instance CLIENTE_B

 ipv4-family

  route-distinguisher 1:300

  vpn-target 300:1 export-extcommunity

  vpn-target 1:300 import-extcommunity

#

- Pe3 ip address configuration

GigabitEthernet0/0/2 interface

 ip binding vpn-instance CLIENTE_B

 ip address 20.20.40.1 255.255.255.0 

#

- Configuration of BGP in PE3

bgp 100

 router-id 7.7.7.7

 peer 1.1.1.1 as-number 100 

 peer 1.1.1.1 connect-interface LoopBack0

 #

 ipv4-family unicast

  undo synchronization

  peer 1.1.1.1 enable

 # 

 ipv4-family vpnv4

  policy vpn-target

  peer 1.1.1.1 enable

 #

 ipv4-family vpn-instance CLIENTE_B 

  import-route direct

  peer 20.20.40.2 as-number 500 

#

Hello @tubaboraka
From the BGP VPNv4 information you upload, the VPNv4 peer relationships between PEs are normal.
Please check the MPLS LSP between the PEs.
In addition, you can check the sent VPNv4 routes through the command 'display bgp vpnv4 vpn-instance vpnb routing-table peer 1.1.1.1 advertised-routes'.