The MPLS WG Archive

[Eric Gray <eric.gray@sandburst.com>]

Shahram,

    In addition to what Jack says below, the intent is to specifically
allow implementations to silently discard packets it might otherwise
be expected to fragment.

Jack Brennen wrote:

> Shahram Davari wrote:
> >
> > Hi all,
> >
> > There seems to be an error in RFC-3032:
> >
> > "3.4. Processing Labeled IPv4 Datagrams which are Too Big
> >  If a labeled IPv4 datagram is "too big", and the DF bit is not set in its IP header, then the LSR MAY silently discard the datagram. ...
> >  If the LSR chooses not to discard a labeled IPv4 datagram which is too big, or if the DF bit is set in that datagram, then it MUST execute the following algorithm:"
> > It seems that the first sentence should read " and if DF bit is set", and the second sentence should read " if DF bit is not set".
> > right?
>
> No, the RFC is correct.  Specifically, the behavior that is mandated
> by the RFC is to generate an ICMP message if an IPv4 packet is too
> large and the DF bit is set.  Silently discarding an IPv4 packet which
> has the DF bit set is not an allowable action.