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BGP in depth lab 8 of 14

Stability and safety nets

One customer leaks a table, another flaps a link all night, and a partner restarts its routing software. Put the safety nets in place on Kestrel Fibre's edge: prefix limits, route-flap dampening, soft reconfiguration and route refresh, and graceful restart between IOS and EOS, then trigger each failure and read what happens.

Run this lab

It needs Lite: its 4 nodes are set to 4 vCPU and 3,328 MB in total. That fits the free demo too.

In your workspace: Shared, then BGP in depth guided labs, then 08 - Stability and safety nets

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Level
Advanced
Time
About 90 minutes
Nodes need
4 vCPU, 3,328 MB
Smallest plan
Lite

The scenario

Kestrel Fibre's edge router, R1, had a bad night. A customer leaked its internal routes, another customer's flapping link kept the routers busy, and a partner's routing restart dropped traffic that could have kept flowing. You've been asked to put in the safety nets, then trigger each failure in the lab to prove they work.

PeerASExpected prefixes
R2645102: 203.0.113.0/26 and 203.0.113.64/26
EOS1645201: 198.51.100.0/24
CHR1645301: 10.100.0.0/24
DeviceInterfaceAddressConnects to
R1Loopback010.255.0.1/32
R1Loopback1192.0.2.1/24
R1Gi0/0172.16.12.1/30R2 Gi0/0
R1Gi0/1172.16.13.1/30EOS1 Ethernet1
R1Gi0/2172.16.14.1/30CHR1 ether1
R2Loopback010.255.0.2/32
R2Loopback1203.0.113.1/26
R2Loopback2203.0.113.65/26
R2Loopback11198.18.1.1/24
R2Loopback12198.18.2.1/24
R2Loopback13198.18.3.1/24
R2Loopback14198.18.4.1/24
R2Gi0/0172.16.12.2/30R1 Gi0/0
EOS1Ethernet1172.16.13.2/30R1 Gi0/1
EOS1Loopback010.255.0.3/32
EOS1Loopback1198.51.100.1/24
CHR1ether1172.16.14.2/30R1 Gi0/2
CHR1lan10.100.0.1/24

What you’ll practise

  • Protect a session with a maximum-prefix limit, a warning threshold and an automatic restart
  • Recognise the Idle (PfxCt) state and the log messages that go with it
  • Explain how soft reconfiguration differs from route refresh, and when each is used
  • Configure route-flap dampening, watch a penalty build and clear a suppressed route
  • Negotiate graceful restart between IOS and EOS, and watch routes stay in place through a BGP restart
  • Set a route limit on RouterOS

The tasks

  1. Prefix limits
  2. Soft reconfiguration or route refresh
  3. Route-flap dampening
  4. Graceful restart
  5. A limit on RouterOS

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 Stability and safety nets4 nodes, 3 links. Every link is listed as text below the diagram.R1R2EOS1CHR1Gi0/0Gi0/0Gi0/1Ethernet1Gi0/2ether1
4 nodes, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • R1 Gi0/0 to R2 Gi0/0
  • R1 Gi0/1 to EOS1 Ethernet1
  • R1 Gi0/2 to CHR1 ether1
Nodes in Stability and safety nets, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
R1Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
R2Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
EOS1Arista vEOSveos-4.33.1.1F1 vCPU, 2,048 MB
CHR1MikroTik RouterOSmikrotik-7.14.21 vCPU, 256 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 08 - Stability and safety nets 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.