Re: Fragment : 2nd Ques

just to add to the mix, isnt this why IPv6 only allows fragmentation by or
at the host not at the router?

so we will need icmp end to end for it to work properly so the security
minded "happy" (great name you have by the way Singh cool...) will need to
be a little more exact in that icmp deny any any at most entry/exit
points...

--
Garry L. Baker
"There is no 'patch' for stupidity." - www.sqlsecurity.com
On Tue, Sep 21, 2010 at 10:45 AM, Pramod G <learn02earn_at_gmail.com> wrote:
> - fragments can take different routes, hence intermediate router may not
> have all information required for reassembly
> - reassembly requires wait time till all the fragments are received, this
> would be time consuming and burden on all intermediate routers performing
> reassembly rather than forwarding packets to destination
>
> Ofcourse the drawback is smaller fragments being transmitted between
> intermediate routers even though there WAN link has higher capacity.
>
>
> On Tue, Sep 21, 2010 at 11:03 AM, Happy Singh <
> happynetworkingsingh_at_gmail.com> wrote:
>
> > Hi
> >
> > Again ; trying to understand Fragmentation .
> > Lets have following scenario :
> >
> > R1 --------R2 ------------R3 ----R4
> >
> > R1-R2 MTU = 3300 bytes
> > R2-R3 MTU = 1300 bytes
> > R3-R4 MTU = 3300 bytes
> >
> >
> > Let pkt of 12000 byte came in R1 . It fragments and send on R1-R2 link
> >
> > R2  must fragment each of these into smaller fragments to send them over
> > the
> > 1,300-byte MTU link. Note that the R3 does *not* reassemble the
> > 1,300-byte fragments, even though next link has an MTU of 3,300
> > bytes.WHYYYYYY ????
> >
> > My question is that why is re-assembly done by end router ? Reasons ?
> >
> > Thnx
> > Happy
> >
> >
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> >
> >
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> >
> >
>
>
> --
> Hi
>
>
> Rgds,
>
> It does not mean a thing, if it can't make a ping!! :-)
>
>
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>
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