Behavior during OSPF premature aging

[Lennard Klein]

Hi,

When premature aging an LSA, bird seems to increase the LSA sequence number to its maximum (proto/ospf/lsupd.c line 616, in 1.4.3).
RFC 2328 14.1 (page 156) states "An LSA can be flushed from the routing domain by setting its LS age to MaxAge, while leaving its LS sequence number alone, and then reflooding the LSA."
While I don’t see a valid technical reason this should break, I seem to have a device in my network which ignores this updates LSA, I suspect it is doing an unsigned int comparison instead of a signed comparison.

While I think the main fault lies with the other vendor, my question at this time is: what is the reasoning behind updating the sequence number to its maximum, even though the RFC says to leave it as-is?

Regards,
Lennard Klein



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