|
midrange.com
I'm familiar with the recommendation of hard coding... i've just never
actually run into a quantifiable problem i've worked on before! I was
always just the 400 guy before and didn't have 'hands on' access to the
rest of the network. Any suggestions are much appreciated...
"Jones, John
\(US\)"
<John.Jones@xxxxx To
l.com> "Midrange Systems Technical
Sent by: Discussion"
midrange-l-bounce <midrange-l@xxxxxxxxxxxx>
s@xxxxxxxxxxxx cc
Subject
11/28/2005 01:10 RE: FTP and file transfer speeds
PM
Please respond to
Midrange Systems
Technical
Discussion
<midrange-l@midra
nge.com>
I basically agree with Larry. 100Mbps equates to a real-world of around
10MBps. 8 bits/byte, of course, + packet & parity overhead means the
theoretical max of 12.5MBps is unachievable. 9-10MBps is about the best
you can expect.
And here, a Cisco shop for years, we've always had to hard-code our
server adapters (both Intel & iSeries) to match the switch vs. leaving
everything on Auto. This was at the request of the network gurus.
--
John A. Jones, CISSP
Americas Information Security Officer
Jones Lang LaSalle, Inc.
V: +1-630-455-2787 F: +1-312-601-1782
john.jones@xxxxxxxxxx
-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Larry Bolhuis
Sent: Monday, November 28, 2005 11:53 AM
To: Midrange Systems Technical Discussion
Subject: Re: FTP and file transfer speeds
Chad,
Clearly you are correct in moving to a switch rather than hub
environment. Setting the iSeries line description to 100Mbps and Full
Duplex are also important. I don't think you have an issue on the
connection from the iSeries to the inside network because 9900+ Mpbs is
fairly close to full network utilization (12000KBps translates roughly
to 100Mbps) You won't get anywhere close to that if the connection is
poor. I would still verify that the switch port is also set to 100Mpbs
and Full duplex rather than AUTO and AUTO, especially with Cisco or Dell
switches. Also verify the current speed and duplex match to the iSeries.
Now the PIX itself will transfer at wire speed but it too can have
problems with speed and duplex. So on the Pix do to SHOW INTERFACE and
observe the reported speed and duplex for the various interfaces. Then
do the same on the switches and observe the ports the PIX is connected
to. I have found that even with Cisco switches the dadgum PIX gets it
wrong. Usually the speed is correct at 100Mpbs but the duplex on the PIX
shows one thing and the switch shows the other. This of course will drag
bandwidth down dramatically.
Of course it makes sense to verify the speed and duplex of the target
server and it's switch port as well.
I'll bet you find a mismatch in there someplace and correcting it will
bring speeds to the DMZ to within 10% of the inside network.
- Larry
ChadB@xxxxxxxxxxxxxxxxxxxx wrote:
> Hello all... i'm working on an file transfer speed issue we first
> noticed while installing some apps to various iSeries boxes on our
> network that are plugged in to various locations/firewall zones.
> Through some more detailed testing, here's what i'm finding.
> Originally, the 'slow' interfaces were plugged in to a 100/half hub
> that provides connectivity to our DMZ zone on our Pix 515. I've since
> replaced that hub with a 100/full switch and reconfigured the *LINDs
> to the new speed/duplex. Some retransmits on the various interfaces I
> was tracking are looking better since the change (2% now on the DMZ
> boxes rather than 4% with the hub), but the file transfers are still
showing the 'SLOW' behavior.
>
> I'm now wondering if this is more of a firewall issue than a
> hardware/config issue... is file transfer throughput between different
> firewall zones impacted this much by a PIX?
>
> Any advice will be appreciated... details are below:
>
>
> With 100/Full switch in place for DMZ connections:
>
|-----------------+-----------------+-----------------+-----------------
|
> |IP Address |Firewall |Time to FTP |Throughput
|
> | |Zone/Hub/Switch |(seconds) |(Kbytes/second)
|
>
|-----------------+-----------------+-----------------+-----------------
|
> |a.a.a.a |Inside |.95 |7000.15
|
>
|-----------------+-----------------+-----------------+-----------------
|
> |b.b.b.b |DMZ |34.34 |194.26
|
>
|-----------------+-----------------+-----------------+-----------------
|
> |c.c.c.c |DMZ |19.23 |346.84
|
>
|-----------------+-----------------+-----------------+-----------------
|
> |d.d.d.d |Inside |3.55 |1880.78
|
>
|-----------------+-----------------+-----------------+-----------------
|
> |e.e.e.e |DMZ |18.63 |358.18
|
>
|-----------------+-----------------+-----------------+-----------------
|
> | | | |
|
>
|-----------------+-----------------+-----------------+-----------------
|
>
>
>
>
> With 100/Half hub in place for DMZ connections:
>
|-----------------+-----------------+-----------------+-----------------
|
> | IP Address | Firewall | Time to FTP | Throughput
|
> | | Zone/Hub/Switch | (seconds) |
(Kbytes/second) |
>
|-----------------+-----------------+-----------------+-----------------
|
> | a.a.a.a | Inside | .67 | 9927.29
|
>
|-----------------+-----------------+-----------------+-----------------
|
> | b.b.b.b | DMZ | 13.56 | 491.86
|
>
|-----------------+-----------------+-----------------+-----------------
|
> | c.c.c.c | DMZ | 32.49 | 205.35
|
>
|-----------------+-----------------+-----------------+-----------------
|
> | d.d.d.d | Inside | 2.28 | 2924.66
|
>
|-----------------+-----------------+-----------------+-----------------
|
> | e.e.e.e | DMZ | 23.25 | 286.92
|
>
|-----------------+-----------------+-----------------+-----------------
|
>
--
Larry Bolhuis IBM eServer Certified Systems Expert:
Vice President iSeries Technical Solutions V5R3
Arbor Solutions, Inc. iSeries LPAR Technical Solutions V5R3
1345 Monroe NW Suite 259 iSeries Linux Technical Solutions V5R3
Grand Rapids, MI 49505 iSeries Windows Integration Technical
Solutions V5R3
IBM eServer Certified Systems Specialist
(616) 451-2500 iSeries System Administrator for
OS/400 V5R3
(616) 451-2571 - Fax AS/400 RPG IV Developer
(616) 260-4746 - Cell iSeries System Command Operations V5R2
If you can read this, thank a teacher....and since it's in English,
thank a soldier.
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