Connecting to the lab server

Open your favourite Terminal Emulator

SSH to the netlab server:

$ ssh-keygen -R netlab.nanocat.net   <- delete the cached fingerprint
                                        (lab server rebuilt frequently)
$ ssh lab@netlab.nanocat.net
Password: (generated fresh each week)

List the running containerlab devices:

$ sudo containerlab inspect --all

Connect to an Arista device:

$ sudo docker exec -it clab-device–name Cli

.. or connect to a Linux device:

$ sudo docker exec -it clab-pcXX-name bash

Goals

• Build a global network with sites in Bucharest, Amsterdam, Berlin, Helsinki and Sydney

Diagram: Global

Diagram: Site

Overview

• Earlier:
  • Create an IP address plan
    • https://docs.google.com/spreadsheets/d/1FevHIOJb1swzmeK_0-NXG5ug7BmXeViMwcAkq4C5ZxQ/edit?usp=sharing
• Now:
  • Configure spanning tree
  • Create a management VLAN
  • Create VLANs for the customers (pc1-pc3)
  • Configure the router
  • Test that PCs can ping one another within a site
• Soon:
  • Configure BGP sessions between your router and the ISP router
  • Advertise and learn the appropriate networks
  • Convert to an L3 leaf-spine
  • Configure iBGP
  • Configure VXLAN
  • Get Layer 2 traffic across the internet like a boss

Configure BGP on your router

Make a BGP connection with the ISP router.

The ISP’s AS number is 65667

!
router bgp 65420
   router-id x.x.x.x
   neighbor x.x.x.x remote-as 65667
   neighbor x.x.x.x description earths-ISP
   network x.x.x.x/x
   network x.x.x.x/x
!

r1.xxx#show ip bgp summary
r1.xxx#show ip route bgp
r1.xxx#show ip bgp neighbor x.x.x.x advertised-routes
r1.xxx#show ip bgp neighbor x.x.x.x received-routes

Do you see the routes?

• BGP won’t advertise a network unless there’s a matching prefix in the local routing table
• Add null0 routes matching your network prefixes

Add null0 routes

!
ip route x.x.x.x/24 null0
ip route x.x.x.x/23 null0
!

r1.xxx#show ip bgp neighbor x.x.x.x advertised-routes

Do you see your remote routes?

• BGP won’t accept a prefix from an eBGP peer, if it sees your own AS in the AS PATH.
• This behaviour can be disabled (carefully) with allowas-in

Enable allowas-in

router bgp 65420
   neighbor x.x.x.x allowas-in
!

r1.xxx#show ip bgp neighbor x.x.x.x advertised-routes
r1.xxx#show ip bgp neighbor x.x.x.x received-routes

Fin! Questions?