Re: Switch Questions

In article <1124726552.628160.58700@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
<bpanders71@xxxxxxxxxxx> wrote:
:I manage a small network (75 desktops, 4 servers) with a single HP
:Procurve 4000m switch which has one 1-port gigabit module and the other
:7 modules having ten 10/100 ports. I've got two HP Proliant DL servers
:with dual gigabit NICS. Obvioulsy, with only one gigabit port, I can
:only hook one of the NICS on one of the servers to it. What I'm
:thinking of doing is purchasing a separate smaller Linksys 16 port
:gigabit switch (under $400) so I can team the dual NICS on both of the
:proliant servers to get 2GB on each. FWIW, the two servers are a
:terminal server which hosts about 15-20 users (currently dual NIC'd at
:200 Mbps), and our main database/file/print server (only one NIC at
:1GBps) which sees some pretty heavy use. Both are win2k.

I'd think it likely that that plan is headed for trouble.


:My questions, therefore, are:

:1) I'm guessing I can plug the Linksys into the Procurve through the
:gigabit port, correct? Should I be using a CAT 6 cable for this or
:will CAT 5e do?

Cat5e will do, at least for moderate distances.


:2) Since the Linksys is a managed switch

Could you check that again? Last time I checked about 3 months ago,
the least expensive *managed* gigabit switch I could find was about $1000.
The $400 Linksys switches were NOT managed at the time.

:I could configure Port
:trunking. Is this something that should always be done when setting up
:dual NICS (primary goal is load balancing with lesser emphasis on fault
:tolerance)?

Port trunking? As in putting in multiple 802.1Q VLANs? That's not going
to help fault tolerance: if your fault tolerance is MAC based then
the MAC in the other VLAN would not be visible; if your fault tolerance
is IP based then the two ports would have to be in different subnets
in order to be able to select the proper port during normal operations.


: I tried port trunking when configuring dual 100 NICS on
:the terminal server, but saw no readily apparent benefit.

Do you perhaps mean port aggregation?

Port aggregation depends on the algorithm being used to distribute
the packets between the available links. I don't recall which algorithms
the Procurves have available. Often the algorithms are based upon
taking the last N bits (2^N >= number of aggregated ports) of the source
or destination and using that as the link index; sometimes the source
and destination bits are xor'd. Unless you have configured per-packet
load balancing on your aggregation ports (I -seem- to recall seeing
that the Procurve could do that), the result is that any one
source + destination MAC pair will always use the same link. Aggregating
N ports does not get you N times the bandwidth (unless per-packet):
instead it gives you opportunities to parallelize up to N different
streams. Like a multilane highway: your car can't drive at 180 miles
per hour just because there are three lanes, but 3 cars can independantly
drive at 60 miles per hour on the three lanes.


:3) Will this scenario actually give me noticeable improvements? I
:don't want to invest even a little bit of money if improvements are
:minimal.

If you are expecting heavy traffic over the gigabit ports, then
chances are that you will be disappointed with the $400 Linksys.
On the consumer gigabit devices, the aggregate throughput supported
is usually fairly low. Many of the consumer gigabit devices use the
same chipset, so you pretty much have to take a jump in price class
in order to get serious simultaneous bandwidth. Something like a
Cisco Cat2960 perhaps; I imagine others will pitch in with other
reliable high-throughput devices. [Note: there have been some reports
of bad experiences with Netgear's line of managed gigabit switches,
which look nice on paper...]
--
Look out, there are llamas!
.

Relevant Pages

  • Re: Switch Questions
    ... >:I manage a small network (75 desktops, 4 servers) with a single HP ... >:Procurve 4000m switch which has one 1-port gigabit module and the other ... >:with dual gigabit NICS. ... >:1) I'm guessing I can plug the Linksys into the Procurve through the ...
    (comp.dcom.lans.ethernet)
  • Re: Switch Questions
    ... >:I manage a small network (75 desktops, 4 servers) with a single HP ... >:Procurve 4000m switch which has one 1-port gigabit module and the other ... >:with dual gigabit NICS. ... Obvioulsy, with only one gigabit port, I can ...
    (comp.dcom.lans.ethernet)
  • Re: Switch Questions
    ... > I manage a small network (75 desktops, 4 servers) with a single HP ... > with dual gigabit NICS. ... Obvioulsy, with only one gigabit port, I can ... Procurve, so unless you're encountering high traffic between servers you're ...
    (comp.dcom.lans.ethernet)
  • Re: Auto-negotiation and traffic flow between different speed ports
    ... >through an uplink port connected at gigabit speeds that the traffic ... >representation of what is happening or does the switch handle traffic ... The internal bus transmits at the maximum internal speeds supported ...
    (comp.dcom.lans.ethernet)
  • Re: I have a 25 PC Workgroup and a PC on the Workgroup keeps printing.
    ... >I have a Computer on a 25 PC Workgroup (no servers) that keeps sending the ... a standard TCP/IP port set up locally. ... Or stomp around the office with a ream of waste paper asking who's print job ... Then figure out which machine is on that switch ...
    (microsoft.public.windowsxp.network_web)