bgp

- research & experiments with border gateway protocol
git clone git://git.acid.vegas/bgp.git
pybgpstream-aspath.py (1511B)
      1 import pybgpstream
      2 import networkx as nx
      3 from collections import defaultdict
      4 from itertools import groupby
      5 
      6 # Create an instance of a simple undirected graph
      7 as_graph = nx.Graph()
      8 
      9 bgp_lens = defaultdict(lambda: defaultdict(lambda: None))
     10 
     11 stream = pybgpstream.BGPStream(
     12     # Consider this time interval:
     13     # Sat, 01 Aug 2015 7:50:00 GMT -  08:10:00 GMT
     14     from_time="2015-08-01 07:50:00", until_time="2015-08-01 08:10:00",
     15     collectors=["rrc00"],
     16     record_type="ribs",
     17 )
     18 
     19 for rec in stream.records():
     20     for elem in rec:
     21         # Get the peer ASn
     22         peer = str(elem.peer_asn)
     23         # Get the array of ASns in the AS path and remove repeatedly prepended ASns
     24         hops = [k for k, g in groupby(elem.fields['as-path'].split(" "))]
     25         if len(hops) > 1 and hops[0] == peer:
     26             # Get the origin ASn
     27             origin = hops[-1]
     28             # Add new edges to the NetworkX graph
     29             for i in range(0,len(hops)-1):
     30                 as_graph.add_edge(hops[i],hops[i+1])
     31             # Update the AS path length between 'peer' and 'origin'
     32             bgp_lens[peer][origin] = \
     33                 min(list(filter(bool,[bgp_lens[peer][origin],len(hops)])))
     34 
     35 # For each 'peer' and 'origin' pair
     36 for peer in bgp_lens:
     37     for origin in bgp_lens[peer]:
     38         # compute the shortest path in the NetworkX graph
     39         nxlen = len(nx.shortest_path(as_graph, peer, origin))
     40         # and compare it to the BGP hop length
     41         print((peer, origin, bgp_lens[peer][origin], nxlen))
     42 
     43