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Add support for ospf auto cost configuration - #1693
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troglobit
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Minor comments, mostly for internal discussion.
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Slight changes to the documentation is suggested.
Also, can we take a look at the YANG changes to auto-cost (agnostic to OSPFv2 or OSPFv3?) and the location of its documentation (under OSPFv2).
All routers in an OSPF domain must use the same reference bandwidth to agree on link costs, and other vendors default to other values than Frr. Until now the value was fixed at the Frr default. Enable the ietf-ospf auto-cost feature for OSPFv2 and OSPFv3. The reference-bandwidth leaf defaults to 100000 Mbit/s, the value used so far, so link costs do not change on upgrade and no migration is needed. Frr can not turn auto-cost off, so the enabled leaf defaults to true and false is rejected. Resolves: #1576 Signed-off-by: Ejub Sabic <ejub1946@outlook.com>
To check that the reference bandwidth matches across the domain it has to be readable. Frr has no JSON for it, so read it from the daemon's running-config, which lists it only when it differs from the default. Report it for OSPFv2 and OSPFv3, and show it in 'show ip ospf' and 'show ipv6 ospf'. Signed-off-by: Ejub Sabic <ejub1946@outlook.com>
Verify that the interface cost follows the reference bandwidth, for OSPFv2 and OSPFv3. The expected cost is derived from the link speed, so the test works on hardware and on virtual links of unknown speed. On a 1 Gbit/s link the reference bandwidths 100000, 10000 and 1000 Mbit/s give the costs 100, 10 and 1. Signed-off-by: Ejub Sabic <ejub1946@outlook.com>
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Explain why the reference bandwidth must match across the domain, how the interface cost is calculated, and where to read the value. Signed-off-by: Ejub Sabic <ejub1946@outlook.com>
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LGTM! |
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Yeah me too, approved the PR for merge! @jovatn we should probably create a doc-task to "consolidate and refactor" routing-dokumentationen. Kan du lägga upp ett? |
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Description
All OSPF routers in a domain need the same auto-cost reference bandwidth
to agree on link costs. Other vendors use other defaults than Frr, so
the value has to be configurable. Resolves #1576.
The
auto-costcontainer from ietf-ospf is now supported, for OSPFv2and OSPFv3:
reference-bandwidthdefaults to 100000 Mbit/s, the Frr default usedso far. Link costs do not change on upgrade, so no migration script
is needed.
enabledis always true. Frr has no way to turn auto-cost off, sosetting it to false is rejected. An explicit interface
coststilloverrides the calculated one.
shown by
show ip ospfandshow ipv6 ospf.The new test
ospf_auto_costruns for both OSPF versions. It sets thereference bandwidth on both routers and checks the interface cost. On
a 1 Gbit/s link, 100000, 10000 and 1000 Mbit/s give the costs 100, 10
and 1.
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