Simple demonstration of "walking LLDP" in a Junos network to create a connection map

junos-walk-lldp.rb

require 'highline/import'
require 'net/netconf/jnpr'

start_at = ARGV[0] || begin
  puts "You need to specify a starting target ip/host"
  exit 1
end

my_username = ENV["USER"]
puts "login: #{my_username}"
my_password = ask("password: "){|a| a.echo = false}


class ScannerLLDP
  
  attr_reader :network_lldp, :devices_ip, :devices_nc
  
  def initialize( name, password )
    @network_lldp = {}
    
    @devices_nc = {}
    @devices_ip = {}
    @visit_list = []
    
    @login = {}
    @login[:username] = name
    @login[:password] = password
  end
  
  def lldp_visit( target_ip )
    
    @login[:target] = target_ip
    puts "Connecting to #{target_ip} ..."
    dev = Netconf::SSH.new( @login )
    dev.open
    
    # record where I am now
    my_lldp = dev.rpc.get_lldp_local_info
    my_lldp_name = my_lldp.xpath('lldp-local-system-name').text
    @devices_nc[my_lldp_name] = dev
    @devices_ip[my_lldp_name] = target_ip
    
    puts "Connected to #{my_lldp_name}"
    
    my_cnx_grid = []
    
    # find the places I need to visit
    nei_nbs = dev.rpc.get_lldp_neighbors_information
    nei_nbs = nei_nbs.xpath('lldp-neighbor-information')
    nei_ports = nei_nbs.xpath('lldp-local-interface | lldp-local-port-id')
    
    nei_ports.each do |nei|
      if_name = nei.text
      
      # get details on the specific interface
      rsp = dev.rpc.command "show lldp neighbors interface #{if_name}"
      if_nei = rsp.xpath('lldp-neighbor-information')
      rmt_sysname = if_nei.xpath('lldp-remote-system-name').text
      rmt_ip = if_nei.xpath('lldp-remote-management-address').text
      
      puts "found #{rmt_sysname}"
            
      my_cnx_grid << { :ifd => if_name, :rmtsys => rmt_sysname }
      
      unless @devices_ip[rmt_sysname]
        puts "--> ADDING #{rmt_sysname}"
        @devices_ip[rmt_sysname] = rmt_ip
        @visit_list << rmt_sysname
      end
      
    end
    @network_lldp[my_lldp_name] = my_cnx_grid
    dev.close
  end  # lldp_visit
  
  def startat( target_ip )
    while target_ip
      lldp_visit( target_ip )
      target_ip = @devices_ip[@visit_list.pop]           
    end
  end
  
  def devices
    @devices_nc.keys
  end
  
  def ncopen( name )
    unless ncdev = @devices_nc[name] 
      puts "Invalid name: #{name}"
    end
    ncdev.open
    ncdev
  end
  
end #class

scanner = ScannerLLDP.new( my_username, my_password )
scanner.startat start_at

# At this point you can examine the network connectivity
# by looking at scanner.network_lldp.
# You can connect to any device using scanner.ncopen <name-learned-via-LLDP>
# and then perform any RPC as normally done using the NETCONF gem
# see https://www.github.com/Juniper-Workflow/net-netconf for more details

junos-walk-lldp.txt

[2] pry(main)> scanner.network_lldp
=> {"EX4200-153"=>
  [{:ifd=>"xe-1/1/1.0", :rmtsys=>"MX240-R132-re0"},
   {:ifd=>"xe-0/1/0.0", :rmtsys=>"MX240-R130-re0"}],
 "MX240-R130-re0"=>
  [{:ifd=>"xe-2/1/2", :rmtsys=>"EX4200-153"},
   {:ifd=>"xe-2/0/2", :rmtsys=>"MX240-R178"},
   {:ifd=>"xe-2/0/3", :rmtsys=>"MX240-R176-re0"},
   {:ifd=>"xe-2/1/0", :rmtsys=>"MX240-R176-re0"},
   {:ifd=>"xe-2/0/0", :rmtsys=>"MX240-R132-re0"},
   {:ifd=>"xe-2/0/1", :rmtsys=>"MX240-R132-re0"}],
 "MX240-R176-re0"=>
  [{:ifd=>"xe-2/1/0", :rmtsys=>"MX480-R244"},
   {:ifd=>"xe-2/1/1", :rmtsys=>"EX4200-139"},
   {:ifd=>"xe-2/0/0", :rmtsys=>"MX240-R132-re0"},
   {:ifd=>"xe-2/0/1", :rmtsys=>"MX240-R132-re0"},
   {:ifd=>"xe-2/0/2", :rmtsys=>"MX240-R130-re0"},
   {:ifd=>"xe-2/0/3", :rmtsys=>"MX240-R130-re0"}],
 "EX4200-139"=>[{:ifd=>"xe-1/1/0.0", :rmtsys=>"MX240-R176-re0"}],
 "MX480-R244"=>[{:ifd=>"xe-5/0/1", :rmtsys=>"MX240-R176-re0"}],
 "MX240-R178"=>[{:ifd=>"xe-2/0/0", :rmtsys=>"MX240-R130-re0"}],
 "MX240-R132-re0"=>
  [{:ifd=>"xe-2/1/0", :rmtsys=>"EX4200-153"},
   {:ifd=>"xe-2/0/2", :rmtsys=>"MX240-R176-re0"},
   {:ifd=>"xe-2/0/3", :rmtsys=>"MX240-R176-re0"},
   {:ifd=>"xe-2/0/0", :rmtsys=>"MX240-R130-re0"},
   {:ifd=>"xe-2/0/1", :rmtsys=>"MX240-R130-re0"}]}