def ospf_net():
graph = NetworkGraph()
r1, r2, r3, r4 = 'R1', 'R2', 'R3', 'R4'
# Add routers
graph.add_router(r1)
graph.add_router(r2)
graph.add_router(r3)
graph.add_router(r4)
# Connect routers
graph.add_router_edge(r1, r2)
graph.add_router_edge(r2, r1)
graph.add_router_edge(r1, r3)
graph.add_router_edge(r3, r1)
graph.add_router_edge(r4, r2)
graph.add_router_edge(r2, r4)
graph.add_router_edge(r4, r3)
graph.add_router_edge(r3, r4)
# Enable OSPF
graph.enable_ospf(r1, 100)
graph.enable_ospf(r2, 100)
graph.enable_ospf(r3, 100)
graph.enable_ospf(r4, 100)
# Assign interfaces
graph.set_iface_names()
# Add networks
for router in graph.routers_iter():
for iface in graph.get_ifaces(router):
graph.add_ospf_network(router, iface, 0)
# Set the edge costs
graph.set_edge_ospf_cost(r1, r2, 100)
graph.set_edge_ospf_cost(r1, r3, 200)
graph.set_edge_ospf_cost(r2, r4, 50)
graph.set_edge_ospf_cost(r3, r4, 300)
# Edge costs for the reverse direction
graph.set_edge_ospf_cost(r4, r2, 100)
graph.set_edge_ospf_cost(r4, r3, 100)
graph.set_edge_ospf_cost(r2, r1, 100)
graph.set_edge_ospf_cost(r3, r1, 100)
# Synthesize connectivity
syn = ConnectedSyn(graph, full=True)
assert syn.synthesize()
# Write the configs
gns3 = GNS3Topo(graph)
tmpdir = tempfile.mkdtemp(suffix='-ospf')
gns3.write_configs(tmpdir)
print("Wrote configurations to %s" % tmpdir)
def two_ibgp_nodes(export_path):
"""
Two routers connected via iBGP
Very simple once router announces a single prefix and the other selects it
"""
graph = NetworkGraph()
r1, r2 = 'R1', 'R2'
graph.add_router(r1)
graph.add_router(r2)
graph.add_router_edge(r1, r2)
graph.add_router_edge(r2, r1)
# BGP configs
graph.set_bgp_asnum(r1, 100)
graph.set_bgp_asnum(r2, 100)
# Establish peering
# The actual network interfaces used for peering will be synthesized
graph.add_bgp_neighbor(r1,
r2,
router_a_iface=VALUENOTSET,
router_b_iface=VALUENOTSET)
# Enable OSPF
graph.enable_ospf(r1, 100)
graph.enable_ospf(r2, 100)
graph.add_ospf_network(r1, 'lo100', 0)
graph.add_ospf_network(r2, 'lo100', 0)
for iface in graph.get_ifaces(r1):
graph.add_ospf_network(r1, iface, 0)
for iface in graph.get_ifaces(r2):
graph.add_ospf_network(r2, iface, 0)
# Some internal network
net = ip_network(u'128.0.0.0/24')
prefix = '128_0_0_0'
prefix_map = {prefix: net}
lo0 = 'lo10'
graph.set_loopback_addr(
r1, lo0, ip_interface("%s/%d" % (net.hosts().next(), net.prefixlen)))
# Announce the internal network
graph.add_bgp_announces(r1, lo0)
# The communities recognized by us
comms = [Community("100:10"), Community("100:20")]
# The announcement that will be propagated by R1
ann = Announcement(prefix=prefix,
peer=r1,
origin=BGP_ATTRS_ORIGIN.EBGP,
next_hop='R1Hop',
as_path=[100],
as_path_len=1,
local_pref=100,
med=100,
communities=dict([(c, False) for c in comms]),
permitted=True)
path = PathReq(Protocols.BGP, prefix, ['R2', 'R1'], False)
reqs = [path]
# Get SMT Context
ctx = create_context(reqs, graph, [ann])
propagation = EBGPPropagation(reqs, graph, ctx)
propagation.compute_dags()
propagation.synthesize()
# SMT Solving
solver = z3.Solver(ctx=ctx.z3_ctx)
assert ctx.check(solver) == z3.sat, solver.unsat_core()
# Update graph with the concrete values after solver
ConnectedSyn([], graph, full=True).synthesize()
propagation.update_network_graph()
gns3 = GNS3Topo(graph=graph, prefix_map=prefix_map)
gns3.write_configs('%s/ibgp-simple' % export_path)
def ibgp_net():
graph = NetworkGraph()
peer, r1, r2, r3, r4 = 'Ext', 'R1', 'R2', 'R3', 'R4'
# Add routers
graph.add_peer(peer)
graph.add_router(r1)
graph.add_router(r2)
graph.add_router(r3)
graph.add_router(r4)
# Connect routers
graph.add_peer_edge(peer, r1)
graph.add_peer_edge(r1, peer)
graph.add_router_edge(r1, r2)
graph.add_router_edge(r2, r1)
graph.add_router_edge(r1, r3)
graph.add_router_edge(r3, r1)
graph.add_router_edge(r4, r2)
graph.add_router_edge(r2, r4)
graph.add_router_edge(r4, r3)
graph.add_router_edge(r3, r4)
# Enable OSPF
graph.enable_ospf(r1, 100)
graph.enable_ospf(r2, 100)
graph.enable_ospf(r3, 100)
graph.enable_ospf(r4, 100)
# Set BGP ASN
graph.set_bgp_asnum(peer, 200)
graph.set_bgp_asnum(r1, 100)
graph.set_bgp_asnum(r2, 100)
graph.set_bgp_asnum(r3, 100)
graph.set_bgp_asnum(r4, 100)
# Establish BGP peering
graph.add_bgp_neighbor(peer, r1)
graph.add_bgp_neighbor(r1, r2)
graph.add_bgp_neighbor(r1, r3)
graph.add_bgp_neighbor(r1, r4)
graph.add_bgp_neighbor(r2, r3)
graph.add_bgp_neighbor(r2, r4)
graph.add_bgp_neighbor(r3, r4)
# Assign interfaces
graph.set_iface_names()
# Some internal to be announced network
net = ip_network(u'128.0.0.0/24')
prefix = '128_0_0_0'
lo0 = 'lo0'
prefix_map = {prefix: net}
loaddr = ip_interface("%s/%d" % (net.hosts().next(), net.prefixlen))
graph.set_loopback_addr(peer, lo0, loaddr)
graph.add_bgp_announces(peer, lo0)
# Synthesize connectivity
syn = ConnectedSyn(graph, full=True, default_ibgp_lo='lo10')
assert syn.synthesize()
# Some route map
actions = [ActionSetLocalPref(200)]
line = RouteMapLine(matches=None,
actions=actions,
access=Access.permit,
lineno=100)
route_map = RouteMap(name="ImpPolicy", lines=[line])
graph.add_route_map(r1, route_map)
graph.add_bgp_import_route_map(r1, peer, route_map.name)
# Add networks
# Note, some of the loop back interfaces where generated due to
# ibgp peering in ConnectedSyn
for router in graph.local_routers_iter():
for iface in graph.get_ifaces(router):
graph.add_ospf_network(router, iface, 0)
for lo in graph.get_loopback_interfaces(router):
graph.add_ospf_network(router, lo, 0)
# Write the configs
gns3 = GNS3Topo(graph, prefix_map=prefix_map)
gns3.write_configs('out-configs/ibgp')