[c-nsp] ip tcp adjust-mss <value> - Alternative?

Hank Nussbacher hank at efes.iucc.ac.il
Sun Jul 3 00:31:26 EDT 2005


At 10:56 PM 01-07-05 +0400, Arie Vayner wrote:

Also:
IP Fragmentation and PMTUD
http://www.cisco.com/en/US/tech/tk827/tk369/technologies_white_paper09186a00800d6979.shtml

-Hank

>Another thing to look at (it's not perfect, but it's something) is
>"Automatically Adjusting the IP MTU".
>Look at this document on CCO:
>
>http://www.cisco.com/en/US/partner/tech/tk801/tk703/technologies_tech_note09186a0080094c4f.shtml
>
>Arie
>CCIE #12198
>
>On 7/1/05, Ran Liebermann <ranmails at gmail.com> wrote:
> > Hi Chris,
> >
> > I agree.
> > Indeed this is a method I like the least (unsetting the DF bit), but
> > some vendors, at least in the BRAS solutions, used to provide just
> > this option.
> >
> > In our network we make sure that all paths that a tunnel can go
> > through will support MTU larger than 1500 bytes plus the tunnel header
> > overhead.
> >
> > (I just noticed that we replied eachother off-list, so I put it back
> > on the list).
> >
> > --
> > Ran.
> >
> >
> > On 29/06/05, [A] <chris at akko.id.au> wrote:
> > > Hi Ran,
> > > Thanks for your response. Apart from effectively disabling PMTUD itself,
> > > what else if anything will clearing the df bit for only TCP packets 
> break in
> > > your experience?
> > >
> > > Obviously what we don't want is to cause more (or bigger) problems 
> than we
> > > actually fix by implementing something like this...
> > >
> > > Regards,
> > > Chris
> > >
> > > ----- Original Message -----
> > > From: "Ran Liebermann" <ranmails at gmail.com>
> > > To: <chris at akko.id.au>
> > > Sent: Wednesday, June 29, 2005 2:26 PM
> > > Subject: Re: [c-nsp] ip tcp adjust-mss <value> - Alternative?
> > >
> > > Either trying harder to increase the MTU throughout the tunnel's path,
> > > or using a route-map to unset the DF bit in packets that have it set
> > > to 1.
> > >
> > > Regards,
> > > --
> > > Ran.
> > >
> > > On 28/06/05, chris at akko.id.au <chris at akko.id.au> wrote:
> > > > Hi list,
> > > > Just wondering what other SP's use as an alternative to the "ip tcp
> > > > adjust-mss" command on platforms that don't support it (e.g. the
> > > > 10008ESR
> > > > PRE2) for working around MTU & fragmentation issues in an L2TP/PPPoE
> > > > LNS
> > > > environment.
> > > >
> > > > Thanks in advance.
> > > >
> > > > Regards,
> > > > Chris
> > > >
> > > > _______________________________________________
> > > > cisco-nsp mailing list  cisco-nsp at puck.nether.net
> > > > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > > > archive at http://puck.nether.net/pipermail/cisco-nsp/
> > > >
> > >
> > >
> >
> > _______________________________________________
> > cisco-nsp mailing list  cisco-nsp at puck.nether.net
> > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > archive at http://puck.nether.net/pipermail/cisco-nsp/
> >
>
>_______________________________________________
>cisco-nsp mailing list  cisco-nsp at puck.nether.net
>https://puck.nether.net/mailman/listinfo/cisco-nsp
>archive at http://puck.nether.net/pipermail/cisco-nsp/
>
>  +++++++++++++++++++++++++++++++++++++++++++
>  This Mail Was Scanned By Mail-seCure System
>  at the Tel-Aviv University CC.



More information about the cisco-nsp mailing list