[c-nsp] Negotiation problem with Catalyst 2950 and Cisco 2821

[Dave Temkin]

I've also seen numerous instances where both Compaq and Intel NICs had
driver issues where they lied about being hard-set to 100/full.  The
driver would report 100/full, however it was obvious from the switch
counters that it was 100/half, and if you set the switch to auto it would
auto to 100/full.



On Sun, 4 Dec 2005, Ted Mittelstaedt wrote:

>
>
> >-----Original Message-----
> >From: cisco-nsp-bounces at puck.nether.net
> >[mailto:cisco-nsp-bounces at puck.nether.net]On Behalf Of C. Jon Larsen
> >Sent: Saturday, December 03, 2005 11:40 AM
> >To: cisco-nsp at puck.nether.net
> >Subject: RE: [c-nsp] Negotiation problem with Catalyst 2950 and
> >Cisco 2821
> >
> >
> >
> >> On 12/3/05, Ted Mittelstaedt <tedm at toybox.placo.com> wrote:
> >> Thanks Reuben, finally someone who isn't a Cisco apologist!  I
> >> figured it would be OBVIOUS to anyone with HALF A BRAIN that
> >> setting autonegotiation on both sides should make it "just work"
> >> out of the box.  This IS cisco-to-cisco gear we are talking about
> >> here.
> >
> >I find it quite odd that as a service provider you would ever
> >trust your
> >network to autonegotiation.
> >
>
> I used to think that way until one day one of our larger customers
> complained about packet loss and excessive latency on X-term
> connections.  (Why they were doing x-protocol over a DSL line and over
> the Internet I'll never know)
>
> When investigating the entire packet path the only thing I could
> find was errors on an Intel Etherrexpress Pro 100 plugged into one of our
> upstream feeds which was coming in over 100BaseT.  (the intel
> card was in a BSD box we were running gated on and running BGP
> on)  That had been set to hard-code.  Setting it to auto and having
> the feed set their hub port to auto fixed the problem.  (we eventually
> changed the BSD box to a 7206VXR because you can't easily support
> ATM coming in on a DS3 with a PC.  Other than that it worked fine)
>
> Today the only thing I automatically hard code are the switch ports
> plugged into the FE ports on our 7206's because those ports do not auto.
> And all our switches are managed these days.  For everything else I
> check the stats on the switch port after plugging in the device.
> Sometimes
> I use hard coding if there's a problem (the Compaq Thunderlan
> texas instruments 10/100 interfaces for example are particular
> problems) but with everything else, autoneg works better.
>
> >
> >With the exception of some cheap nics (and older drivers on windows
> >servers) I have never seen hardcoding **both** sides to full
> >duplex 10 or
> >100 fail to produce good results.
>
> You can only do this when your plugged into a managed switch.  At
> the NOC everything is managed, but it's a different story with most
> of our customers.  Even the customers that do have managed switches
> (which are few) often don't have management turned on.
>
> >Failing to set speed and duplex will
> >(even if it works at first) usually bite you down the road i.e.
> >typically
> >in a late nite reboot situation when it fails and one side is full and
> >the other side is in half (the default).
> >
> >
> >That being said autonegotiate **should** work in most cases,
> >but why leave
> >it to chance for anything important like a switch to switch or a switch
> >to router or switch to customer handoff ? Ciscos have always had
> >autonegotiate problems, dating back to the 5000 and 5500 switches, its
> >nothing new.
> >
>
> Most of our customer handoffs are ethernet ports on 1600's, 1700's 1800's
> that are at the end of T1's and the router is at the customer site, or
> they
> are ethernet ports on DSL modems at the customer site.  While most of
> the DSL stuff goes right into cheap routers, the Cisco gear usually runs
> NAT and goes into anything imaginable.
>
> >Even with Bay and 3com switches (which do seem to work better with
> >autonegotiate) I always hardcoded (to full duplex) the server side with
> >mii-tool and the switch side with whatever tool the switch OS provides.
> >Guess I am old fashioned.
> >
>
> Ebay 3com managed switches (like the desktop 3300 which is an excellent
> and cheap Ebay switch) would be a step up for what 70% of our customers
> are using.
>
> Ted
>
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