From: Corey Hickey <bugfood-ml@fatooh.org>
To: Julian Anastasov <ja@ssi.bg>
Cc: Linux Netdev List <netdev@vger.kernel.org>
Subject: Re: strange routing issue--packets stop getting forwarded for a live connection
Date: Thu, 25 Aug 2011 20:50:03 -0700 [thread overview]
Message-ID: <4E5717EB.6030304@fatooh.org> (raw)
In-Reply-To: <alpine.LFD.2.00.1108211142180.1581@ja.ssi.bg>
On 2011-08-21 02:02, Julian Anastasov wrote:
>>>> 3. MTU size; 1500 on eth0 and 1406 on tun0. Bigger packets have been
>>>> transferred fine.
>>>
>>> Lower MTU, it can be PMTUD problem. At 04:50:24.112658
>>> I see 7801:9169 is 1420 bytes and no ICMP FRAG NEEDED is generated.
>>> May be these two regressions explain it:
>>>
>>> http://marc.info/?l=linux-netdev&m=131342172722536&w=2
>>>
>>> There are 2 fixes you can try or more recent kernel
>>> tree, for example 3.1-rc2 has the fixes.
>>
>> Many thanks for your reply--it looks like you're on to something. You
>> didn't specify which interface to lower the MTU on, so I tried them each
>> in turn, and found that lowering the MTU on the client machine to 1406
>> (matching tun0 on the router) did indeed solve the problem. That makes
>> sense in retrospect.
>
> I just wanted to note the difference in MTUs
> as a possible cause that triggers the problem. And after
> your confirmation I think the new/patched kernel should work
> without playing with MTUs.
I finally got a chance to test this, and the patched kernel works fine.
Thank you!
-Corey
prev parent reply other threads:[~2011-08-26 3:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-21 2:15 strange routing issue--packets stop getting forwarded for a live connection Corey Hickey
2011-08-21 6:35 ` Julian Anastasov
2011-08-21 8:12 ` Corey Hickey
2011-08-21 9:02 ` Julian Anastasov
2011-08-26 3:50 ` Corey Hickey [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4E5717EB.6030304@fatooh.org \
--to=bugfood-ml@fatooh.org \
--cc=ja@ssi.bg \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.