You say they are unnecessary, then why do we have vendors doing this wrong and pointing to this requirement of the RFC as their reason for doing so?
While there may be a valid argument that they shouldn’t be necessary, I would argue that real world implementation experience suggests that they are most definitely necessary and are a minor edit to provide additional clarity. Are you really arguing to preserve ambiguous language when the problem is so easy to solve? Owen > On Sep 17, 2023, at 15:25, Acee Lindem <[email protected]> wrote: > > Given that the context of the “Interface MTU” is specifically the “interface > MTU” field in OSPFv3 Database Description packets and OSPF virtual links (RFC > 2328), the additions recommended in this Errata are unnecessary. The Errata > should be rejected. > > Thanks, > Acee >> On Sep 17, 2023, at 15:58, RFC Errata System <[email protected]> >> wrote: >> >> The following errata report has been submitted for RFC5838, >> "Support of Address Families in OSPFv3". >> >> -------------------------------------- >> You may review the report below and at: >> https://www.rfc-editor.org/errata/eid7644 >> >> -------------------------------------- >> Type: Technical >> Reported by: Owen DeLong <[email protected]> >> >> Section: 2.7 >> >> Original Text >> ------------- >> Interface MTU >> The size in octets of the largest address family specific datagram >> that can be sent on the associated interface without >> fragmentation. The MTUs of common Internet link types can be >> found in Table 7-1 of [MTUDISC]. The Interface MTU SHOULD be set >> to 0 in Database Description packets sent over virtual links. >> >> >> Corrected Text >> -------------- >> Interface MTU >> The size in octets of the largest address family specific datagram >> that can be sent on the associated interface without >> fragmentation. The MTUs of common Internet link types can be >> found in Table 7-1 of [MTUDISC]. The Interface MTU SHOULD be set >> to 0 in Database Description packets sent over (OSPF3) virtual links. >> This recommendation MUST NOT be applied to tunnel and other virtual >> or software interfaces which carry traffic other than OSPF protocol >> packets. >> >> Notes >> ----- >> Currently, the language is ambiguous and at least one vendor has implemented >> OSPF3 sending an MTU of zero on GRE interfaces (and possibly others such as >> IPIP, IPSEC, etc., as I have not tested these). I believe that the intent of >> the RFC is to refer strictly to OSPF virtual-links which carry only OSPF >> protocol data and therefore have no meaningful MTU. When this is mistakenly >> applied to other forms of "virtual" interfaces such as tunnels, the results >> can be quite harmful. >> >> As such, I think that clarification is in order, since the vendor in >> question is unrepentant and claims their current implementation to be >> compliant with the RFC. >> >> Instructions: >> ------------- >> This erratum is currently posted as "Reported". If necessary, please >> use "Reply All" to discuss whether it should be verified or >> rejected. When a decision is reached, the verifying party >> can log in to change the status and edit the report, if necessary. >> >> -------------------------------------- >> RFC5838 (draft-ietf-ospf-af-alt-10) >> -------------------------------------- >> Title : Support of Address Families in OSPFv3 >> Publication Date : April 2010 >> Author(s) : A. Lindem, Ed., S. Mirtorabi, A. Roy, M. Barnes, R. >> Aggarwal >> Category : PROPOSED STANDARD >> Source : Open Shortest Path First IGP >> Area : Routing >> Stream : IETF >> Verifying Party : IESG >> >> _______________________________________________ >> Lsr mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/lsr > _______________________________________________ Lsr mailing list [email protected] https://www.ietf.org/mailman/listinfo/lsr
