Exabgp peering

check-v4.rb

#!/usr/bin/ruby

require 'socket'

# our IP here
@target = 'x.212'
# bind these to lo using ip addr add x.x.x.x/32 dev lo
@routes = %w[ x.245/32 x.8/32 x.6/32 x.22/32 x.7/32 ]
@sockfile = '/var/run/pdns_recursor.controlsocket'
@state = :announce

STDOUT.sync = true

def sockname
  (('0'..'9').to_a + ('A'..'Z').to_a + ('a'..'z').to_a).sample(8).join('') + "." + Process.pid.to_s
end

def test
  ret = false

  lpath = File.join File.dirname(@sockfile), sockname

  begin
    s = Socket.new(:UNIX, :DGRAM, 0)
    s.bind Socket.sockaddr_un lpath
    File.chmod 0666, lpath
    s.connect Socket.sockaddr_un @sockfile

    s.send 'ping', 0
    if IO.select([s], nil, nil, 1).nil? == false
      s.recv(10)
      ret = true
    end

    s.close
  rescue
  end

  File.unlink lpath
  return ret
end

def announce
  return unless @state == :announce

  @routes.each do |r|
    print "announce route #{r} next-hop #{@target} med 50 local-preference 50 community [ 16086:16086 ]\n"
  end
  print "flush routes\n"

  @state = :withdraw
end

def withdraw
  return unless @state == :withdraw

  @routes.each do |r|
    print "withdraw route #{r} next-hop #{@target} med 100 local-preference 50 community [ 16086:16086 ]\n"
  end
  print "flush routes\n"

  @state = :announce
end

def main
#  print "version exabgp 3.3.0\n"

  while true
    if test
      announce
    else
      withdraw
    end

    sleep 1
  end
end

main

check-v6.rb

#!/usr/bin/ruby

require 'socket'

# our IP here
@target = '2001:14b8:1000:1::3:100'
# bind these to lo using ip addr add x:x::x/128 dev lo
@routes = %w[ x:1000::1/128 ]
@sockfile = '/var/run/pdns_recursor.controlsocket'
@state = :announce

STDOUT.sync = true

def sockname
  (('0'..'9').to_a + ('A'..'Z').to_a + ('a'..'z').to_a).sample(8).join('') + "." + Process.pid.to_s
end

def test
  ret = false

  lpath = File.join File.dirname(@sockfile), sockname

  begin
    s = Socket.new(:UNIX, :DGRAM, 0)
    s.bind Socket.sockaddr_un lpath
    File.chmod 0666, lpath
    s.connect Socket.sockaddr_un @sockfile

    s.send 'ping', 0
    if IO.select([s], nil, nil, 1).nil? == false
      s.recv(10)
      ret = true
    end

    s.close
  rescue
  end

  File.unlink lpath
  return ret
end

def announce
  return unless @state == :announce

  @routes.each do |r|
    print "announce route #{r} next-hop #{@target} med 100 local-preference 50 community [ 16086:16086 ]\n"
  end
  print "flush routes\n"

  @state = :withdraw
end

def withdraw
  return unless @state == :withdraw

  @routes.each do |r|
    print "withdraw route #{r} next-hop #{@target} med 100 local-preference 50 community [ 16086:16086 ]\n"
  end
  print "flush routes\n"

  @state = :announce
end

def main
#  print "version exabgp 3.3.0\n"

  while true
    if test
      announce
    else
      withdraw
    end

    sleep 1
  end
end

main

exabgp.conf

neighbor x.x.x.209 {
  # our IP address
  router-id x.x.x.212;
  local-address x.x.x.212;
  local-as x;
  peer-as x;
  hold-time 21;
  group-updates;

  capability {
    asn4;
  }

  process watchdog-1 {
    run /etc/exabgp/processes/check-v4.rb;
  }
}

neighbor x::3:1 {
  # SAME as above
  router-id x.212;
  # our IP
  local-address x::3:100;
  # same as above
  local-as x;
  peer-as x;
  hold-time 21;
  group-updates;

  capability {
    asn4;
  }

  process watchdog-2 {
    run /etc/exabgp/processes/check-v6.rb;
  }
}