One of the nice things about network namespaces is that they allow one to easily create and test complex environments.
Unfortunately, these namespaces can not be used with actual switching ASICs, as their ports can not be migrated to other network namespaces (NETIF_F_NETNS_LOCAL) and most of them probably do not support the L1-separation provided by namespaces.
However, a similar kind of flexibility can be achieved by using VRFs and by looping the switch ports together. For example:
br0 + vrf-h1 | vrf-h2 + +---+----+ + | | | | 192.0.2.1/24 + + + + 192.0.2.2/24 swp1 swp2 swp3 swp4 + + + + | | | | +--------+ +--------+
The VRFs act as lightweight namespaces representing hosts connected to the switch.
This approach for testing switch ASICs has several advantages over the traditional method that requires multiple physical machines, to name a few:
1. Only the device under test (DUT) is being tested without noise from other system.
2. Ability to easily provision complex topologies. Testing bridging between 4-ports LAGs or 8-way ECMP requires many physical links that are not always available. With the VRF-based approach one merely needs to loopback more ports.
These tests are written with switch ASICs in mind, but they can be run on any Linux box using veth pairs to emulate physical loopbacks.
Feedback is is welcome. Particularly regarding the best location for these tests (e.g., current location, tools/testing/selftests/net).
Thanks.
Ido Schimmel (7): selftests: forwarding: Add initial testing framework selftests: forwarding: Add a test for FDB learning selftests: forwarding: Add a test for flooded traffic selftests: forwarding: Add a test for basic IPv4 and IPv6 routing selftests: forwarding: Create test topology for multipath routing selftests: forwarding: Test IPv4 weighted nexthops selftests: forwarding: Test IPv6 weighted nexthops
Jiri Pirko (5): selftests: forwarding: Add tc offload check helper selftests: forwarding: Add MAC get helper selftests: forwarding: Allow to get netdev interfaces names from commandline selftests: forwarding: Allow to pass commandline options selftests: forwarding: Introduce tc flower matching tests
tools/testing/selftests/Makefile | 1 + tools/testing/selftests/forwarding/.gitignore | 1 + tools/testing/selftests/forwarding/Makefile | 6 + tools/testing/selftests/forwarding/README | 56 +++ tools/testing/selftests/forwarding/bridge.sh | 117 +++++++ tools/testing/selftests/forwarding/config | 12 + .../selftests/forwarding/forwarding.config.sample | 19 + tools/testing/selftests/forwarding/lib.sh | 383 +++++++++++++++++++++ tools/testing/selftests/forwarding/router.sh | 131 +++++++ .../selftests/forwarding/router_multipath.sh | 321 +++++++++++++++++ tools/testing/selftests/forwarding/tc_flower.sh | 261 ++++++++++++++ 11 files changed, 1308 insertions(+) create mode 100644 tools/testing/selftests/forwarding/.gitignore create mode 100644 tools/testing/selftests/forwarding/Makefile create mode 100644 tools/testing/selftests/forwarding/README create mode 100755 tools/testing/selftests/forwarding/bridge.sh create mode 100644 tools/testing/selftests/forwarding/config create mode 100644 tools/testing/selftests/forwarding/forwarding.config.sample create mode 100644 tools/testing/selftests/forwarding/lib.sh create mode 100755 tools/testing/selftests/forwarding/router.sh create mode 100755 tools/testing/selftests/forwarding/router_multipath.sh create mode 100755 tools/testing/selftests/forwarding/tc_flower.sh