This is true, but in a half-duplex environment, collisions dont'
cause much of a performance drop, as when one side detects a
collision, it will send a jamming signal to the other side so it will
shut up and traffic can continue. If one side is half and the other
is full, the jamming signal is ignored and the two will continue to
try to talk over each other and traffic creaps to a halt. A device
that is HD will clear the collision counter it generated every time a
frame is successfully transmitted after a jam signal is sent, so you
generally don't see collision counters on a HD device, if it is
working in accordance to the ethernet specs. That's CSMA/CDs nifty
little trick to keep you from panicking when you see your error
counters in a network that is supposed to have collisions (well, not
supposed to I guess, but *will* :-))
--
Aubrey Wells
Senior Engineer
Shelton | Johns Technology Group
404.478.2790
www.sheltonjohns.com
On Sep 21, 2007, at 12:43 AM, Peter Wohlers wrote:
I guess thinking about it more, and in the spirit of not propagating
misinformation, collisions are normal in any half-duplex environment.
Whether there's actually a mismatch or not is just how we're
conditioned to
view it because 100-half really doesn't buy you much but faster
collisions ;)
Full duplex environments should by definition, not have any
collisions.
--Peter
Aubrey Wells wrote:
I would have TWTC force their side to 100 Full, and you do the
same on
yours. Collisions, 99% of the time, only occur as a result of a
duplex
mismatch.
*
*
*--*
*Aubrey Wells*
/Senior Engineer/
Shelton | Johns Technology Group
404.478.2790
www.sheltonjohns.com
On Sep 20, 2007, at 7:10 PM, Jeff wrote:
On the 7206 the interfaces are FastEthernet interfaces
I did try each one from auto to force, etc and did not seem to make
any difference
But I was not trying to much. Till I asked some pointers
Maybe its something I will have to have Timewarner match the
switch to
my ethernet card, no idea for sure
Jeff
*From:* Allan Leinwand [mailto:[EMAIL PROTECTED]
*To:* 'Jeff' [mailto:[EMAIL PROTECTED],
vyatta-users@mailman.vyatta.com
mailto:vyatta-users@mailman.vyatta.com,
vyatta-users@mailman.vyatta.com
mailto:vyatta-users@mailman.vyatta.com
*Sent:* Thu, 20 Sep 2007 17:36:42 -0400
*Subject:* RE: [Vyatta-users] Errors On Outgoing Ethernet
Interface
Hi Jeff,
I'd guess that you're having an issue with the auto
negotiation
of speed and/or duplex on that interface. You can set these
commands as follows:
vyatta mailto:[EMAIL PROTECTED]# set interfaces ethernet eth0
duplex ?
Possible completions:
autoSet duplex auto-negotiation mode
full Set full duplex mode
half Set half duplex mode
I'd make sure you're set for auto on both speed and duplex
and
if that does not work I'd try to force the interface into a
setting that you know will work. show interfaces on your 7206
can show you the current settings.
Take care,
allan
*From:* [EMAIL PROTECTED]
mailto:[EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]
mailto:[EMAIL PROTECTED]] *On Behalf
Of *Jeff
*Sent:* Thursday, September 20, 2007 2:23 PM
*To:* vyatta-users@mailman.vyatta.com
mailto:vyatta-users@mailman.vyatta.com;
vyatta-users@mailman.vyatta.com
mailto:vyatta-users@mailman.vyatta.com
*Subject:* [Vyatta-users] Errors On Outgoing Ethernet Interface
I finally got to do a test run on vyatta today for the 1st run.
I have two ethernet interfaces setup one for lan the other
for the
wan connected to TimeWarner
I unplugged my 7206vxr cisco
And plugged in the two ethernet interfaces from it into my
vyatta box
At any rate all seemed fine I could ping in and out, my
ipaddresses asgned were visable.
All looked great, but then I logged into the vyatta web
interface,
and seen that the ethernet interface going to the wan
to tme warner switch was poplulting errors in the amount of 5
errors at a time every so many seconds
At anyrate I viewed the interface and seen it was showing
colisions.
The ethernet interface to the local lan had no errors at all.
So after a little more runtime I plugged back into the cisco,
(No
errors) and all was totally fine again.
Any ideas what may be causing these errors?
I have built the vyatta on a Vision 1GHz Pent 3 with 1 gig
ram and
80 gig harddrive (basically overkill)
Anyway the two ethernet cards are built into the motherboard..
Jeff
