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DUPLEX MISMATCH BUG MESSEAGE
http://forum.gns3.net/topic8276-10.html
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Author:  flaviojs [ Sun Mar 30, 2014 12:28 am ]
Post subject:  Re: DUPLEX MISMATCH BUG MESSEAGE

Btw, I'm going for full-duplex because I think most devices use full-duplex nowadays. Feel free to correct me if I'm wrong.

Author:  flaviojs [ Mon Mar 31, 2014 8:29 am ]
Post subject:  Re: DUPLEX MISMATCH BUG MESSEAGE

I poked around until I noticed this particular difference in the 10Mbit case:
* 'show controllers' says ADM unknown
* 'show interfaces' says AmdP2

I have no idea what chip AmdP2 is supposed to use, but I suspect it's not the Am79c971 being emulated.

The only difference between the 10Mbit and 100Mbit versions is the chip id register.
It's being sent properly for 100Mbit and 0 for 10Mbit, which explains the AMD unknown.
If I send the chip id for 10Mbit, they will appear as fast-ethernet interfaces... xD

Guess I'm stuck until I get samples of 'show interfaces' and 'show controller' with real ethernet slot/wic hardware. (note: I prefer 'show tech-support' since there should be other useful info)
Can someone provide samples for me?

PS-I need samples to know which chip/controller should be emulated

Author:  flaviojs [ Sat Apr 05, 2014 1:38 pm ]
Post subject:  Re: DUPLEX MISMATCH BUG MESSEAGE

Progress!

On a whim I decided to try lower numbers for the PARTID of the chip, since a 10Mb/s card is probably older.
I got lucky, "AMD Presidio" was just 2 numbers away (0x2621). \o/
It still doesn't tell me the chip model, but at least now I can compare with the PARTID in the datasheets.
...(searching Am79C* datasheets at random)...
Bingo, it's Am79C970A! I'm lucky today, maybe I should buy a lottery ticket? =)


And... Roadblock!

The datasheet doesn't talk about auto-negotiation so it's not supported. =(
Using the PARTID for Am79C970A (AMD Presario):
"duplex ?" confirms that auto isn't available.
"show run" confirms that half-duplex is the default for these ethernet interfaces.


It's looking grim...
either someone gives me info about a 10Mb/s ethernet where IOS has "duplex auto"
or I find a way to make IOS treat an existing FastEthernet as Ethernet. =~~
(hmm, maybe create a fabricated NM-4FE that would probably still show up as NM-4E= in "show diag"?)

Author:  flaviojs [ Sat Apr 12, 2014 9:13 am ]
Post subject:  Re: DUPLEX MISMATCH BUG MESSEAGE

The more acceptable alternative ideas for auto-negotiation I've been having:
  • hypervisor command to get/set auto-negotiation values (we would be passive)
  • central channel for physical data interactions (heavy: unique id for each interface, ability to link-in external dynamips, which interface is at the other end)
  • adapt or use an existing protocol. ex: adapt LOOP with custom function ids or use LLDP (how would it work with hubs?)
  • intercept CDP packets and either "fix" them or auto-adjust itself to match the data (they trigger the warning, non-dynamips hardware can still get at least one warning)

Author:  flaviojs [ Tue Apr 15, 2014 1:13 pm ]
Post subject:  Re: DUPLEX MISMATCH BUG MESSEAGE

Related topic: topic9324.html

Author:  Tony.Davis [ Thu Apr 17, 2014 9:04 pm ]
Post subject:  Re: DUPLEX MISMATCH BUG MESSEAGE

"Normally, 10-Mb/s ports operate in half-duplex mode, which means that stations can either receive or send traffic..."

http://www.cisco.com/c/en/us/td/docs/sw ... swint.html

And this explains in better detail:

http://www.speedguide.net/articles/ethe ... ation-2184


basically, 10Mb has no auto-negotiate mechanism and defaults to half-duplex. I think the easiest thing to do is to disable cdp duplex mismatch, or hardcode your ports to full duplex.

Author:  grossmj [ Thu Apr 17, 2014 9:07 pm ]
Post subject:  Re: DUPLEX MISMATCH BUG MESSEAGE

Quote:
I think the easiest thing to do is to disable cdp duplex mismatch


I've done this with the default base startup-config provided with the new GNS3 :)

Author:  flaviojs [ Fri Apr 18, 2014 12:17 am ]
Post subject:  Re: DUPLEX MISMATCH BUG MESSEAGE

I'm exploring another possibility right now.
If I make a 10/100 ethernet chip report that it only has capabilities for 10Mbps,
and if IOS actually checks that information (instead of making assumptions) to decide if it's an ethernet or fast ethernet interface,
then we can have 'official' 10Mbps ethernet interfaces with auto negotiation.

I'm not very hopeful. Since they also decide the chips that are used, the drivers don't need to be generic.
Regardless, completing the emulation of a piece of hardware (chip) is also progress. xD

Author:  anubisg1 [ Fri May 16, 2014 8:46 am ]
Post subject:  Re: DUPLEX MISMATCH BUG MESSEAGE

honestly i hardcode speed 100 duplex full, and i solve any problem...

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