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To: "James Knott" <james.knott,AT,rogers,DOT,com>
Subject: Re: Slow file sharing performance
From: "Hans Steegers" <hsx,AT,dds,DOT,nl>
Date: Mon, 1 Sep 2003 10:44:06 +0200
Cc: <cipe-l,AT,inka,DOT,de>
Reply-to: "Hans Steegers" <steegers,AT,steegers,DOT,nl>

>There are no firewall rules that apply to the VPN traffic.  The internet
>connection, that the VPN passes through doesnsn't see the SMB or NFS
>traffic, because they're encrypted in the tunnel packets.
Of course, but a typo is easily made and overlooked causing filtering
between the LAN and CIPE interface...
Also: ICMP traffic can be involved for routing CIPE's UDP packets...

> CIPE automatically adjusts the MTU as required, but I have also tried
> smaller packets, without any improvement.
The so called MTU problem is not CIPE's but other's having problems with
CIPE's 1442 or 1428 MTU.

From the CIPE mailing list:
==
The problem is well-known to those who are using a pppoe connection via a
router to connect to the internet via DSL.  This ppp interface has an MTU of
1492 and causes the same trouble.
Using google I found a short descriptions of the problem at
    http://blue-labs.org/howto/mtu-mss.php
..
Christoph
==
I can't find other reasons for this asymmetrical behaviour.

How large is the speed difference anyway?
If 50% or less, fragmentation may be the cause (twice the overhead).

Hans Steegers

-----Original Message-----
From: James Knott <james.knott,AT,rogers,DOT,com>
To: Hans Steegers <steegers,AT,steegers,DOT,nl>
Date: Monday, September 01, 2003 2:46 AM
Subject: Re: Slow file sharing performance

>Hans Steegers wrote:
>> 1. Suspect your firewall(s) dropping ICMP or other (SMB/NFS) protocol
>> related packets. Try it without the firewalls, to be sure.
>
>There are no firewall rules that apply to the VPN traffic.  The internet
>connection, that the VPN passes through doesnsn't see the SMB or NFS
>traffic, because they're encrypted in the tunnel packets.
>
>> 2. Set on both sides cttl in your options file: cttl 64
>> Encryption doesn't require a fast CPU: a 486 is sufficient for a
>> ADSL/CABLE/DIALUP connection.
>> 3. Or (maybe) you have got a MTU problem: search the CIPE archives for
more
>> info.
>
>Cttl is already set to 64.  CIPE automatically adjusts the MTU as
>required, but I have also tried smaller packets, without any improvement.
>
>>
>> I hope this helps..
>>
>> Hans Steegers
>> -----Original Message-----
>> From: James Knott <james.knott,AT,rogers,DOT,com>
>> To: CIPE <cipe-l,AT,inka,DOT,de>
>> Date: Sunday, August 31, 2003 1:53 PM
>> Subject: Re: Slow file sharing performance
>>
>>
>>
>>>Jon Bendtsen wrote:
>>>
>>>>James Knott wrote:
>>>>
>>>>
>>>>>I've notice that while my CIPE VPN works, that SMB and NFS access of
>>>>>my home network from my notebook is slow.  However, going the other
>>>>>way, accessing file shares on my notebook, from my home lan is fine.
>>>>>I'm connecting from my notebook, via dialup ISP and cable modem to my
>>>>>home network.
>>>>>
>>>>>Why is this problem in only one direction?  Is it due to the speed
>>>>>difference between my home network and dial up modem?
>>>>
>>>>
>>>>Well, i can think of 2 reasons. The most likely is that you have a
>>>>different upload and download speed, like 2048kbits down, and 512 up.
>>>>The other reason could be that one end is much much faster than at home.
>>>>Suppose you have a recent notebook, then you have at least 500mhz+, if
>>>>not 1ghz+. At home you might have your old pentium 90mhz as a cipe gw.
>>>>Thus, when you send stuff from home, the p90 has to encrypt it, and
>>>>when you send from your notebook that one has to encrypt it. (I'm
>>>>guessing here that encryption takes longer time than decryption.
>>>
>>>One computer is a 1.113 GHz PIII, the other is an Athlon XP 1700.  I'd
>>>suspect both ends have sufficient horsepower.  Also, when watching the
>>>data lights flash, it's apparent that the data transfer stops entirely
>>>for quite a while.  I would expect transfers to be slower due to the
>>>dial up connection, but not stopped.  The vastly slower dialup
>>>connection would rule out the asymetrical cable modem speeds as a cause
>>>of the problem.  As I mentioned, it only happens in the one direction.
>>>
>>>The firewall is a 166 MHz Pentium and is running about 99% idle.  Also,
>>>ftp transfers work fine, along with other protocols, such as telnet, ssh
>>>and X.  The problem appears to occur only with SMB and NFS and only in
>>>that one direction.
>>>
>>>tnx jk
>>>
>>>
>>>
>>>--
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>>>Unsubscribe: mail majordomo,AT,inka,DOT,de, "unsubscribe cipe-l" in body
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>>>CIPE info and list archive:
>>
>> <URL:http://sites.inka.de/~bigred/devel/cipe.html>
>>
>
>


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