8-ccie-routing-switching-implement-bgp-m8-slides.pdf

8/11/2019 8-ccie-routing-switching-implement-bgp-m8-slides.pdf

1/7

Multiprotocol BGP (MBGP)

Joe Astorino

www.astorinonetworks.com

@jastorino


2/7

Introduction to MBGP

BGP-4 was originally intended to carry only IPv4 route information

However, modern networks require information from potentially

many other sources to be shared between organizations on a large

scale

Rather than inventing new protocols to carry this information, BGPwas modified with multiprotocol extensions in RFC 2283

MBGP allows us to use BGP to carry route information for many

different things

IPv4 unicast and multicast IPv6 unicast and multicast

IPv4 or IPv6 route information within a customer VRF

VPNv4 for use in MPLS L3 VPN

Others and likely more in the future


3/7

MBGP Attributes

MBGP uses two new BGP attributes Multiprotocol Reachable NLRI (MP_REACH_NLRI)

Multiprotocol Unreachable NLRI (MP_UNREACH_NLRI)

The MP_REACH_NLRI attribute contains the reachable prefixes for a

particular address-family

The MP_UNREACH_NLRI attribute contains the unreachable or

withdrawn prefixes for a particular address-family

Each of these attributes will contain one or more AFI (address family

information) that communicates the protocols the prefixes beingadvertised apply to (IPv4, IPv6, etc)

Sub-AFI (SAFI) will communicate weather the AFI is used for unicast,

multicast or both


4/7


5/7

Configuring MBGP

router bgp 65100

neighbor 2001:100:100:1::1 remote-as 65001

neighbor 192.168.111.1 remote-as 65001

!

address-family ipv4 unicastredistribute connected route-map CONNECTED-BGP

neighbor 192.168.111.1 activateneighbor 192.168.111.1 send-community

neighbor 192.168.111.1 prefix-list R1-OUT out

!

address-family ipv4 multicastredistribute connected route-map CONNECTED-BGP

neighbor 192.168.111.1 activate

neighbor 192.168.111.1 send-community

!

address-family ipv6 unicastneighbor 2001:100:100:1::1 activate

neighbor 2001:100:100:1::1 send-community

network 2001:100:100:100::1/64


6/7

Verifying MBGP

MBGP carries more than just IPv4, so it made sense to change thestructure of the show commands

Legacy Syntax: show ip bgp

You can still use this but be aware that it only shows IPv4 AFI information!

Good idea to get into the habit of the new syntax for everything

Modern Syntax: show bgp

show bgp ipv4 unicast summary

show bgp ipv4 unicast

show bgp ipv4 multicast show bgp vpnv4 neighbor 1.1.1.1 advertised-routes

show bgp all


7/7

Verifying MBGP

R1#show bgp ipv4 unicast summary | b Neighbor

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/DownState/PfxRcd

2.2.2.2 4 65123 3293 2960 4141 0 0 13:01:38 18

3.3.3.3 4 65123 3269 2964 4141 0 0 13:01:34 14

192.168.111.100 4 65100 2432 2874 4141 0 0 10:20:15 8

R1#show bgp ipv6 unicast | b NetworkNetwork Next Hop Metric LocPrf Weight Path

*> 2001:100:100:100::/64 2001:100:100:1::100 0 100 0 65100 i

R1#show bgp ipv6 unicast summary | b NeighborNeighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd

2001:100:100:1::100 4 65100 633 632 2 0 0 10:22:45 1

Documents

8-ccie-routing-switching-implement-bgp-m8-slides.pdf