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BGP in depth lab 5 of 14

Route reflectors and cluster design

Kestrel Fibre's five core routers run a full iBGP mesh, and the sixth is on order. Replace the mesh with route reflectors, read the attributes that stop a reflected route from looping, and find out the hard way why two reflectors that share a cluster ID can leave a hole in your routing.

Run this lab

It needs Lite: its 6 nodes are set to 6 vCPU and 4,608 MB in total. That fits the free demo too.

In your workspace: Shared, then BGP in depth guided labs, then 05 - Route reflectors and cluster design

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Level
Advanced
Time
About 90 minutes
Nodes need
6 vCPU, 4,608 MB
Smallest plan
Lite

The scenario

Kestrel Fibre's core has five routers in AS 64500, all on one core LAN, and a full iBGP mesh between their loopbacks. C1 is the Internet edge. C2 and C3 hold customers. RR1 and RR2 are new, and you're going to make them the route reflectors. C3 is an Arista switch from the last acquisition, so you'll read the same attributes in two vendors' words.

DeviceRoleLoopback0Prefix it originates
RR1Route reflector10.255.0.1
RR2Route reflector10.255.0.2
C1Client, Internet edge10.255.0.11
C2Client10.255.0.12203.0.113.0/26
C3Client (EOS)10.255.0.13203.0.113.64/26
E1AS 64999, the Internet198.51.100.0/24
DeviceInterfaceAddressConnects to
RR1Loopback010.255.0.1/32
RR1Gi0/010.0.0.1/24Core
RR2Loopback010.255.0.2/32
RR2Gi0/010.0.0.2/24Core
C1Loopback010.255.0.11/32
C1Gi0/010.0.0.11/24Core
C1Gi0/1172.16.100.1/30E1 Gi0/0
C2Loopback010.255.0.12/32
C2Loopback1203.0.113.1/26
C2Gi0/010.0.0.12/24Core
C3Ethernet110.0.0.13/24Core
C3Loopback010.255.0.13/32
C3Loopback1203.0.113.65/26
E1Loopback010.255.0.99/32
E1Loopback1198.51.100.1/24
E1Gi0/0172.16.100.2/30C1 Gi0/1

What you’ll practise

  • Count the sessions a full mesh needs and explain why iBGP needs one
  • Configure route reflectors and clients on IOS, and a client on EOS
  • Read ORIGINATOR_ID and CLUSTER_LIST on a reflected path
  • Explain why a reflector leaves the next hop alone, and what that means for the exit routers
  • Show how a shared cluster ID drops reflected routes, and when that causes an outage
  • Design reflector redundancy with different cluster IDs and prove it survives lost sessions

The tasks

  1. Count the mesh
  2. One route reflector
  3. The loop protection attributes
  4. A second reflector with the same cluster ID
  5. Find the hole
  6. Fix it with different cluster IDs
  7. Restore the sessions

The Lab Tasks pane has the scenario, these tasks, the checks to run, hints and the full solution.

Topology and devices

The network as it opens in EVE-NG, drawn from the lab’s own canvas, and the image each node runs.

Topology of Route reflectors and cluster design6 nodes and 1 network, 6 links. Every link is listed as text below the diagram.RR1RR2C1C2C3E1CoreGi0/1Gi0/0Gi0/0Gi0/0Gi0/0Ethernet1Gi0/0
6 nodes and 1 network, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • RR1 Gi0/0 to Core (network)
  • RR2 Gi0/0 to Core (network)
  • C1 Gi0/0 to Core (network)
  • C2 Gi0/0 to Core (network)
  • C3 Ethernet1 to Core (network)
  • C1 Gi0/1 to E1 Gi0/0
Nodes in Route reflectors and cluster design, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
RR1Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
RR2Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
C1Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
C2Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
C3Arista vEOSveos-4.33.1.1F1 vCPU, 2,048 MB
E1Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB

How to open this lab

  1. Sign in to your workspace at lab.cloudlabbox.com.

  2. In File Manager, open Shared, then the folder BGP in depth guided labs.

  3. Open 05 - Route reflectors and cluster design and start its nodes, then open Lab Tasks for the scenario and the steps.

The lab is read-only. You can start the nodes and configure the devices, but changes to the topology can’t be saved. To change it, rebuild it in your own folder.

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CloudLabBox is independent of Arista Networks, Cisco, Juniper Networks and MikroTik. The lab follows exam topics and isn’t vendor training material; vendor names identify the exams and the images in the workspace.