What are BGP commands?

Table of Contents

BGP Commands

Command	Description
bgp router-id [A.B.C.D]	Configure the router ID.
network [A.B.C.D/M]	Announce BGP on network: A.B.C.D/M, identifies the subnet to advertise.
no network [A.B.C.D/M]	Disable BGP announcements on network A.B.C.D/M
ipv6 bgp network [A:B:C:D:E:F:G:H/M]	Announce BGP on network.

How does MPLS L3VPN work?

MPLS L3VPN is a type of PE-based L3VPN technology for service provider VPN solutions. It uses BGP to advertise VPN routes and uses MPLS to forward VPN packets on service provider backbones. MPLS L3VPN provides flexible networking modes, excellent scalability, and convenient support for MPLS QoS and MPLS TE.

How do I configure MPLS?

The six basic steps in the configuration are as follows:

Configure the loopback interface to be used as the LDP router ID.
Enable CEF.
Configure the label distribution protocol.
Configure the TDP/LDP router ID (optional).
Configure MPLS on core interfaces.
Configure IS-IS or OSPF as the MPLS VPN backbone IGP.

What is the command to check BGP status?

To display information about the TCP and BGP connections to neighbors, use the show ip bgp neighbors command in EXEC mode. Syntax Description address (Optional) Address of the neighbor whose routes you have learned from. If you omit this argument, all neighbors are displayed.

How can I check my BGP status?

What is difference between l2vpn and L3VPN?

Layer 2 VPNs virtualize the datalink layer (Layer 2) so as to make geographically remote sites look as if they were operating in the same LAN network. Layer 3 VPNs virtualize the network layer (Layer 3) so as to route your customer networks over a public infrastructure like Internet or Service provider backbone.

What is RD and RT in BGP?

The Route-Distinguisher (RD) & Route-Target (RT) are two different concepts that are both used in an MPLS VPN. The RD is used to keep all prefixes in the BGP table unique, and the RT is used to transfer routes between VRF’s/VPNS.

What is MPLS IP command?

The mpls ip command enables MPLS routing. Multiprotocol Label Switching (MPLS) is a networking process that avoids complex lookups in a routing table by replacing complete network addresses with short path labels for directing data packets to network nodes.

What is the BGP community for l3vpns?

BGP community is a good way to solve this problem. For L3VPNs a specific extended community was defined in RFC 4364 Section 4.3.1 called Route Target. RFC 4364.

What are the prerequisites to set up L3VPN?

Another prerequisite is to have an MPLS enabled core, since L3VPN uses MPLS encapsulation for dataplane communication. I configured RSVP-TE tunnels between PE routers for this tutorial in the way that PE1_ALU can resolve PE2_JUN (and vice versa) loopback address via RSVP-TE tunnel.

How are VPN-IPv4 routes distributed in BGP?

When a VPN-IPv4 route is created (from an IPv4 route that the PE has learned from a CE) by a PE router, it is associated with one or more Route Target attributes. These are carried in BGP as attributes of the route. Any route associated with Route Target T must be distributed to every PE router that has a VRF associated with Route Target T.

Is BGP configured on router P?

No BGP is configured on router P. Note: The command neighbor 10.1.1.3 send-community extended is automatically configured under the address-family vpnv4 section. Note: The command neighbor 10.1.1.1 send-community extended is automatically configured under the address-family vpnv4 section.