# test_ospf6_ecmp_inter_area.py
#
-# Copyright (c) 2021, 2022 by Martin Buck
+# Copyright (c) 2021, 2022, 2024 by Martin Buck
# Copyright (c) 2016 by
# Network Device Education Foundation, Inc. ("NetDEF")
#
r"""
test_ospf6_ecmp_inter_area.py: Test OSPFv3 ECMP inter-area nexthop update
-Check proper removal of ECMP nexthops after a path used by one nexthop
-disappears. We remove a path by bringing down a link required by that
-path which is not adjacent to the router being checked. This is important
-because when bringing down adjacent links, the kernel might remove the
-nexthops itself without ospf6d having to do anything.
+Check proper addition and removal of ECMP nexthops in 2 cases: Parallel
+paths to one ABR and parallel ABRs. We test nexthop removal triggered by
+path removal by bringing down a link required by that path which is not
+adjacent to the router being checked. This is important because when
+bringing down adjacent links, the kernel might remove the nexthops itself
+without ospf6d having to do anything.
-Useful as a regression test for #9720.
+Useful as a regression test for #9720 and #15777.
Topology:
- .
- Area 0 . Area 1
- .
- -- R2 -- . ---- R6
- / \ ./
-R1 -- R3 -- R5 ---- R7 Area 1
- \ / \\ ..............
- -- R4 -- \--- R8 Area 0
- \
- -- R9
-
-We check routes on R1, primarily those towards R6/7/8/9. Those to R6/7 are
-inter-area routes with R5 being ABR, those to R8/9 are intra-area routes
-and are used for reference. R6/R8 announce external routes, R7/R9 announce
-internal routes.
+ .
+ Area 0 . Area 1
+ .
+ -- R2 ------ R5 -----
+ / .\ \
+ / . | \
+R1 --- R3 ------ R6 ------ R7
+ \ / |. |
+ \ / |. |
+ -- R4 ---- |. |
+ / ./
+ R8 --
+ .
+
+We check routes on R1, primarily those towards R7/8. Those to R7 are
+inter-area routes with R5/6 being ABRs, those to R8 are intra-area routes
+and are used for reference. R7/R8 announce one internal and one external
+route each.
With all links up, we expect 3 ECMP paths and 3 nexthops on R1 towards each
-of R6/7/8/9. Then we bring down the R2-R5 link, causing only 2 remaining
-paths and 2 nexthops on R1. The test is successful if the number of nexthops
-for the routes on R1 is as expected.
+of R7/8. Then we bring down the R3-R6 link, causing only 2 remaining
+paths and 2 nexthops on R1. Then we bring down the R2-R5 link, causing only
+1 remaining path and 1 nexthop on R1.
+
+The test is successful if the number of nexthops for the routes on R1 is as
+expected.
"""
import os
def build_topo(tgen):
"Build function"
- # Create 9 routers
- for routern in range(1, 10):
+ # Create 8 routers
+ for routern in range(1, 9):
tgen.add_router("r{}".format(routern))
-
tgen.gears["r1"].add_link(tgen.gears["r2"])
tgen.gears["r1"].add_link(tgen.gears["r3"])
tgen.gears["r1"].add_link(tgen.gears["r4"])
tgen.gears["r2"].add_link(tgen.gears["r5"])
- tgen.gears["r3"].add_link(tgen.gears["r5"])
- tgen.gears["r4"].add_link(tgen.gears["r5"])
- tgen.gears["r5"].add_link(tgen.gears["r6"])
+ tgen.gears["r3"].add_link(tgen.gears["r6"])
+ tgen.gears["r4"].add_link(tgen.gears["r6"])
tgen.gears["r5"].add_link(tgen.gears["r7"])
tgen.gears["r5"].add_link(tgen.gears["r8"])
- tgen.gears["r5"].add_link(tgen.gears["r9"])
+ tgen.gears["r6"].add_link(tgen.gears["r7"])
+ tgen.gears["r6"].add_link(tgen.gears["r8"])
+ # Additional "loopback" interfaces. Not used for communication, just to
+ # hold an address we use to inject intra-/inter-area routes (the one on
+ # the real "lo" loopback is used for external routes).
+ tgen.gears["r7"].add_link(tgen.gears["r7"])
+ tgen.gears["r8"].add_link(tgen.gears["r8"])
def setup_module(mod):
expect_neighbor_full("r2", "10.254.254.1")
expect_neighbor_full("r2", "10.254.254.5")
expect_neighbor_full("r3", "10.254.254.1")
- expect_neighbor_full("r3", "10.254.254.5")
+ expect_neighbor_full("r3", "10.254.254.6")
expect_neighbor_full("r4", "10.254.254.1")
- expect_neighbor_full("r4", "10.254.254.5")
+ expect_neighbor_full("r4", "10.254.254.6")
expect_neighbor_full("r5", "10.254.254.2")
- expect_neighbor_full("r5", "10.254.254.3")
- expect_neighbor_full("r5", "10.254.254.4")
- expect_neighbor_full("r5", "10.254.254.6")
expect_neighbor_full("r5", "10.254.254.7")
expect_neighbor_full("r5", "10.254.254.8")
- expect_neighbor_full("r5", "10.254.254.9")
- expect_neighbor_full("r6", "10.254.254.5")
+ expect_neighbor_full("r6", "10.254.254.3")
+ expect_neighbor_full("r6", "10.254.254.7")
+ expect_neighbor_full("r6", "10.254.254.8")
expect_neighbor_full("r7", "10.254.254.5")
+ expect_neighbor_full("r7", "10.254.254.6")
expect_neighbor_full("r8", "10.254.254.5")
- expect_neighbor_full("r9", "10.254.254.5")
+ expect_neighbor_full("r8", "10.254.254.6")
def test_ecmp_inter_area():
pytest.skip(tgen.errors)
def num_nexthops(router):
- routes = tgen.gears[router].vtysh_cmd("show ipv6 ospf6 route json", isjson=True)
- route_prefixes_infos = sorted(routes.get("routes", {}).items())
- return [len(ri.get("nextHops", [])) for rp, ri in route_prefixes_infos]
+ # Careful: "show ipv6 ospf6 route json" doesn't work here. It will
+ # only list one route type per prefix and that might not necessarily
+ # be the best/selected route. "show ipv6 route ospf6 json" only
+ # lists selected routes, so that's more useful in this case.
+ routes = tgen.gears[router].vtysh_cmd("show ipv6 route ospf6 json", isjson=True)
+ route_prefixes_infos = sorted(routes.items())
+ # Note: ri may contain one entry per routing protocol, but since
+ # we've explicitly requested only ospf6 above, we can count on ri[0]
+ # being the entry we're looking for.
+ return [ri[0]["internalNextHopActiveNum"] for rp, ri in route_prefixes_infos]
def expect_num_nexthops(router, expected_num_nexthops, count):
"Wait until number of nexthops for routes matches expectation"
), "'{}' wrong number of route nexthops".format(router)
# Check nexthops pre link-down
- expect_num_nexthops("r1", [1, 1, 1, 3, 3, 3, 3, 3, 3, 3], 4)
+ # tgen.mininet_cli()
+ expect_num_nexthops("r1", [1, 1, 1, 1, 2, 3, 3, 3, 3], 4)
+
+ logger.info("triggering R3-R6 link down")
+ tgen.gears["r3"].run("ip link set r3-eth1 down")
+
+ # tgen.mininet_cli()
+ # Check nexthops post link-down
+ expect_num_nexthops("r1", [1, 1, 1, 1, 1, 2, 2, 2, 2], 8)
- logger.info("triggering R2-R4 link down")
+ logger.info("triggering R2-R5 link down")
tgen.gears["r2"].run("ip link set r2-eth1 down")
# tgen.mininet_cli()
# Check nexthops post link-down
- expect_num_nexthops("r1", [1, 1, 1, 2, 2, 2, 2, 2, 2, 2], 8)
+ expect_num_nexthops("r1", [1, 1, 1, 1, 1, 1, 1, 1, 1], 8)
def teardown_module(_mod):
projects / matthieu / frr.git / commitdiff