[hpsdr] Hermes and Ethernet Switch Mystery

[Tim O'Rourke]

I use the Trendnet switch below.
There is a DSL modem which connects to Linksys wireless/wired router.
One line from router runs to one port on the switch. Another port goes to Hermes and a 3rd port to shack PC. All works FB.
Tim 


-----Original Message-----
>From: "Joe Giacobello, K2XX" <k2xx at swva.net>
>Sent: Dec 12, 2012 11:30 AM
>To: hpsdr at lists.openhpsdr.org
>Cc: hpsdr-request at lists.openhpsdr.org
>Subject: [hpsdr] Hermes and Ethernet Switch Mystery
>
>***** High Performance Software Defined Radio Discussion List *****
>
>Many thanks to Frank, Dave and John regarding my Ethernet switch 
>problems.  I couldn't get either of the two low cost full duplex 
>switches to work (Zuni ZS105F and Trendset TEG-S50g).The Zuni is 100 Mbs 
>and the Trendset is  2000 Mbs in full duplex.  Based on what little I've 
>been able to learn, there are various performance levels of switches and 
>the more capable ones are relatively expensive.  The ones that I tried 
>were less than $20 each.
>
>After fiddling with my network settings without success, I bit the 
>bullet and scavenged an old PCI NIC card from a retired computer and 
>installed it in my shack computer. It's now working perfectly with the 
>Hermes and PSDR.
>
>John, I am using a DSL modem/router here with ports throughout the house 
>via CAT5 cable. (I also have a wireless  access point.)  I had checked 
>the LED behavior on my Hermes when I originally got it up and running, 
>and they seemed to be behaving correctly.  However, I didn't recheck 
>them when I was having the communications problems with the computer.  I 
>should go back and do that.  I believe that I did try just connecting 
>the Hermes and the computer via the switch without success, but I should 
>go back and recheck that too.
>
>At any rate, now that I have the Hermes conveniently and routinely 
>linked with my computer, I can go ahead and fully integrate it into the 
>shack and compare its receiver with those of my "conventional" transceivers.
>
>Thanks to all for the help.
>
>73, Joe
>K2XX
>
>
>
>
>
>On 12/11/2012 5:07 PM, hpsdr-request at lists.openhpsdr.org wrote:
>> From: John Marvin<jm-hpsdr at themarvins.org>
>> To:hpsdr at lists.openhpsdr.org
>> Subject: Re: [hpsdr] Hermes and Ethernet Switch Mystery
>> Message-ID:<50C66EED.80609 at themarvins.org>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> Joe, you haven't mentioned whether or not the switches you tried are at
>> least 100 Mbit capable (if not they must be fairly old switches). If
>> they are then the problem is most likely not the switch you are using,
>> since you say that they are full duplex and appear to work properly as
>> part of your computers connection to the internet.
>>
>> my guess is that you have an issue with how Hermes gets its IP address.
>> When directly connected both the PC and Hermes will use APIPA addresses
>> in the 169.254.x.x range once their DHCP requests fail. When they aren't
>> directly connected both the Hermes and your PC will send DHCP requests,
>> where one may succeed and the other fail. If they both do not get
>> responses then it should work the same as if they were directly
>> connected (assuming your switch functions properly and is full duplex).
>>
>> The question is where is the DHCP server on your network and how is it
>> configured? If your PC gets a DHCP address and the Hermes does not then
>> your PC will be on a "different" network than the Hermes, which will
>> come up using an APIPA address. If you consult the Hermes User Manual
>> page 16 documents the meaning of various LED's, and there is a group of
>> 10 leds together that contains "LED7" which indicates what the DHCP
>> status for the board is. If the led is flashing rapidly this indicates
>> that the DHCP request timed out and Hermes is using an APIPA address.
>>
>> In most cases your DHCP server is going to be either a router or
>> cable/DSL modem on your network (it will depend on whether or not a
>> router is built into your "modem"). Since you've tried multiple
>> switches, most likely the issue is your DHCP server configuration,
>> although in most cases the default configuration should be adequate for
>> almost any home network. Have you customized your DHCP configuration?
>>
>> If you absolutely want to verify that the switch is not the problem then
>> you should try just connecting your PC and your Hermes to the switch
>> without connecting anything else to the switch (i.e. the rest of your
>> home network where you DHCP server most likely resides). This would
>> essentially be the same scenario as a direct connection, i.e. both your
>> PC and Hermes will be using APIPA addresses. If this works then your
>> switch is not the issue. If it doesn't then make sure that the switch is
>> at least 100 Mbit capable and/or try yet another switch.
>>
>> If you still can't find the problem it would be helpful if you share
>> more about your network topology.
>>
>> John
>> AC0ZG
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Tim O'Rourke 
W4YN at ARRL.Net
Low Power Amateur Radio Rocks 
Member of Flying Pigs,ARCI,GQRP,RSGB,ARRL Life Member
NHRA Life Member

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