[hpsdr] Hermes and Ethernet Switch Mystery

[Joe Giacobello, K2XX]

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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