Fw: [Bugme-new] [Bug 1148] New: when using ipsec with DSL connections communication will hang if mtu is 1500(the default value)

Fw: [Bugme-new] [Bug 1148] New: when using ipsec with DSL connections communication will hang if mtu is 1500(the default value)

[Andrew Morton]

Begin forwarded message:

Date: Tue, 26 Aug 2003 00:07:57 -0700
From: bugme-daemon@osdl.org
To: bugme-new@lists.osdl.org
Subject: [Bugme-new] [Bug 1148] New: when using ipsec with DSL connections communication will hang if mtu is 1500(the default value)


http://bugme.osdl.org/show_bug.cgi?id=1148

           Summary: when using ipsec with DSL connections communication will
                    hang if mtu is 1500(the default value)
    Kernel Version: 2.6.0-test4
            Status: NEW
          Severity: normal
             Owner: bugme-janitors@lists.osdl.org
         Submitter: uwe.schmeling@t-online.de


Distribution:
Hardware Environment:
Software Environment:
Problem Description:

Steps to reproduce: 
Startup a tunneling connection, if one of the gw interfaces has mtu=1500,
communication will hang after transfering some data through tunnel. As far as I
know the problem will occure with DSL connections only.

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.

Re: Fw: [Bugme-new] [Bug 1148] New: when using ipsec with DSL connections communication will hang if mtu is 1500(the default value)

[David S. Miller]

On Tue, 26 Aug 2003 00:39:49 -0700
Andrew Morton <akpm@osdl.org> wrote:

> Begin forwarded message:

We don't do PMTU properly in tunneled mode, known problem
but fix won't happen any time soon as it's non-trivial
to cure this properly.

Re: Fw: [Bugme-new] [Bug 1148] New: when using ipsec with DSL connections communication will hang if mtu is 1500(the default value)

[Michael Richardson]

>>>>> "Andrew" == Andrew Morton <akpm@osdl.org> writes:
    Andrew> Distribution:
    Andrew> Hardware Environment:
    Andrew> Software Environment:
    Andrew> Problem Description:

    Andrew> Steps to reproduce: 
    Andrew> Startup a tunneling connection, if one of the gw interfaces has
    Andrew> mtu=1500, 
    Andrew> communication will hang after transfering some data through
    Andrew> tunnel. As far as I 
    Andrew> know the problem will occure with DSL connections only.

  If by "DSL", you mean PPPoE, then you are dealing with layers of tunnels.

  This sure sounds like a classif pmtud blackhole problem.

]      Out and about in Ottawa.    hmmm... beer.                |  firewalls  [
]   Michael Richardson, Sandelman Software Works, Ottawa, ON    |net architect[
] mcr@sandelman.ottawa.on.ca http://www.sandelman.ottawa.on.ca/ |device driver[
] panic("Just another Debian/notebook using, kernel hacking, security guy");  [

Re: Fw: [Bugme-new] [Bug 1148] New: when using ipsec with DSL connections communication will hang if mtu is 1500(the default value)

[David S. Miller]

On Tue, 26 Aug 2003 16:59:42 -0400
Michael Richardson <mcr@sandelman.ottawa.on.ca> wrote:

>   This sure sounds like a classif pmtud blackhole problem.

Regardless of his configuration, we don't propagate PMTU's
over tunneled IPSEC connections properly at all.