01-04-2010 04:33 PM
Let's hope this works. From the release notes, it appears I will have
to set the speed setting to 100M mode. Once I did this, my managed
Gigabit switch indicated the port is now at 100TX mode.
However, the switch also indicated the connection is now Half duplex
instead of Full duplex. I believe this drops the throughput
even more when the traffic is high through the WAP. It seems the
WAP autonegotiated to Half duplex mode. Is this correct and
is it necessary?
01-04-2010 04:50 PM
01-05-2010 12:56 AM
Hi Guys,
I think from discussions we are now looking at a autonegotiation issue. A lot of folks forget what auto negotiation does, because they don't have to worry about this on a daily basis.
I appreciate that everyone who reads this post knows what autonegotiation is, so I say the following with sincere humility.
Auto-negotiation is a protocol that a switch port is in, usually by default. If the device attached to a switch port it is not in autonegotiation mode, but MANUALLY altered to 100meg full duplex, that attached device is obviously not in auto-negotiation mode.
If a device attached to a switch port is manually altered to 100mFull duplex, then the switch port also should be manually altered to 100Mfull duplex.
Why, because, there is no possibility of the auto negotiation process to complete between the two ethernet hosts.
If the the device attached to a switch port is manually attached at 100mFull duplex, but the switch port is still in autonegotiation mode, that switch port may try to unsuccessfully negotiate a speed and may settle for 100mHalf duplex, because it is not getting a response to it's autonegotiation 'challenge.'
So the behaviour you mention, indicates to me that a switch port may still be in auto negotiation mode.
The moral of the story is;
1.If one host speed and duplex is manually altered, the attached host must also be manually altered to the same speed and duplex. Auto negotiation setting WILL NOT work, even advertising100M Full duplex, because the other host will not respond to autonegotiation.
2. Simply put, since the wireless side is running a bit like a old fashion hub, almost a shared collision prone ethernet environment, your WAP4410N is still providing much faster bandwidth for AP users, when compared to a 54Meg wireless G AP environment..But sounds like new firmware is available to resolve this issue.
Good luck and Regards
Dave
Cisco Small Business, Channel Systems Engineer
01-05-2010 03:23 AM
This is exactly the theory explained within one of the previous attachments (Speed and Duplex Matrix.pdf).
Now the question from the WAP4410 perspective is;
1) How do we see and know whether the WAP4410 is set via GUI to “Force LAN Port Speed to 100M” works on 100Mb/FD or in 100Mb/HD (half duplex)?
2) What is the reason for increasing RX errors on the switch end and increasing “Drop Received Packets” on the WAP4410 end while the switch is forced to 100/FD and the WAP4410 is set via GUI to “Force LAN Port Speed to 100M”? Within my opinion this indicates a duplex mismatch!
3) What is the interpretation of below CLI output while the WAP4410 is set via GUI to “Force LAN Port Speed to 100M”?
Observations:
Conclusion:
*************
[VAP0 @ Cisco-WAP4410N-POE]# set ethdatarate
ethdatarate auto -- Auto detect
ethdatarate 1000 -- 1000Mbps
ethdatarate 100 -- 100Mbps
ethdatarate 10 -- 10Mbps
[VAP0 @ Cisco-WAP4410N-POE]# set ethdatarate 100
Warning: Force LAN Port Speed to 100M is enabled, disable it first to set ethernet data rate here.
[VAP0 @ Cisco-WAP4410N-POE]# get ethdatarate
Ethernet Data Rate: Auto
[VAP0 @ Cisco-WAP4410N-POE]# set ethdatarate 100
Ethernet Data Rate: 100Mbps
[VAP0 @ Cisco-WAP4410N-POE]# get ethdatarate
Ethernet Data Rate: 100Mbps
*************
01-05-2010 04:06 AM
Hi Ismarkusem,
Data you posted above with the release notes i just looked at, which states "Enable this feature to force the link speed of the LAN port of the
access point to be at 100 Mbps" brings up another question.
Is it only advertising 100m via autonegotiation or is it fixing 100mFull duplex. I would prefer to see the port status via the gui, but without that data and only the data you posted, it sure looks like, it is just in autonegotiating, but now not advertising 1000MBit/sec .
I would hazard a guess that if you set the switch port to autonegotiate, the switch port would settle to 100mFull duplex, when the WAP4410N is set to force the link speed to 100Bbps. If that is the case, it would seem that the new software is autonegotiating, but not advertising 1000mHalf or Full.
Agreed, yes RX errors on the switch would indicate maybe a duplex mismatch :(.
If you can set both switch port and the WAP4410N to 100mFull, and avoid autonegotiation, why not just leave it at that setting?
I will have a word to the WAP4410N Product manager (when he's back from vacation) to get a better explaination of what is meant by "force the link speed of the LAN port of the access point to be at 100 Mbps"
I will update this post
regards Dave
01-05-2010 09:53 AM
WAP4410N Firmware v 2.0.0.12 is now available for download without login at: http://www.cisco.com/en/US/products/ps10052/index.html.
Select "Download Firmware and Accept License Agreement for this Product".
Thank you.
01-06-2010 03:23 PM
I passed your question to Engineering and was informed that, when the access point is configured to negotiate 100M speed with "Force LAN Port Speed to 100M" enabled in firmware v2.0.0.12, some gigabit switches will have half duplex speed due to various switch specifications. The next firmware release will provide an improved solution for auto-negotiating speed between the AP and the switch.
Stay tuned.
Thanks
01-07-2010 10:18 AM
Stephanie,
Will this to be released firmware you mention fix all issues or will a V2 hardware RMA be necessary. thanks for the update!!!
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