Re: SMB's proposal: using an IP option for "Report Fragmentation" flag
Philippe Prindeville <philipp@gipsi.gipsi.fr> Tue, 28 November 1989 15:10 UTC
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Date: Tue, 28 Nov 1989 16:10:13 -0100
From: Philippe Prindeville <philipp@gipsi.gipsi.fr>
Message-Id: <8911281510.AA02552@gipsi.gipsi.fr>
Phone: +33 1 30 60 75 25 / +33 1 47 34 42 74
To: mogul
Subject: Re: SMB's proposal: using an IP option for "Report Fragmentation" flag
Cc: MTU Discovery <mtudwg>
Steve B's proposal (introduce a new "flag" IP Option that means "Report Fragmentation") has several nice advantages. First, it doesn't appear to require any changes to existing gateway implementations (which are all required to pass along unknown options, subject to the usual orthogonal rules about copying on fragmentation). Second, it doesn't intrude on any "architecture resource" scarcities (i.e., bits in the IP header). This may sound a little heretical, but perhaps we are considering fragmentation "Not Harmful Enough"? Maybe fragmentation really should be looked upon as something quite severe and that *any* fragmentation should be reported via an ICMP message back to the source. This way, no options or header bits are used. We would have to allocate a new ICMP message type, though: reason being it must be something that hosts not yet equiped with this MTU discovery code can safely ignore (albiet at the cost of much degraded performance -- if the performance is bad enough, perhaps the users will bang on the management to upgrade to a more reasonable release). Anyway, just using Fragmentation Required But Not Permitted (or whatever, I don't have 791 handy) with a different Code would not be adequate. -Philip
- Re: SMB's proposal: using an IP option for "Repor… Steve Deering
- Re: SMB's proposal: using an IP option for "Repor… Philippe Prindeville
- Re: SMB's proposal: using an IP option for "Repor… Jeffrey Mogul
- Re: Another proposal to think about Jeffrey Mogul
- Re: SMB's proposal: using an IP option for "Repor… Jeffrey Mogul
- Re: Another proposal to think about William Westfield
- Re: SMB's proposal: using an IP option for "Repor… Philippe Prindeville
- Re: yet another MTU discovery scheme Jeffrey Mogul
- Re: Minutes of MTU Discovery Working Group Meetin… Jeffrey Mogul
- Re: routing protocols will provide path-MTU Jeffrey Mogul
- Re: number of octets returned in ICMP error messa… Jeffrey Mogul