[hpsdr] Metis and DHCP and LinkSys Routers

[w3sz]

Just a note for those who may be seeing 'funny things' in terms of IP 
address assignment when starting Metis.
At my QTH I use only 'true' switches on the LAN.
I have a LinkSys BEFSR11 Router that is the DHCP server for my network 
(assigning IP addresses to my wife's and daughters' fixed and portable 
devices; my computers all have fixed IP addresses).
I found that Metis would not successfully get an IP address from the 
Router.  The Router and Metis would exchange a round of 2 
Discover-Offer-Request-NAK sequences and then Metis would get an APIPA 
address.  Metis works fine with that.

I decided to see if setting up a DHCP server on my Linux mailserver 
would provide a DHCP server that would succeed in giving Metis an IP 
address.  I found that just activating the DHCP server on the Linux box 
would allow the LinkSys Router to give Metis an IP address.  I know that 
the IP address was coming from the Router and not the Linux box DHCP 
server because [1] I limited the Linux box to addresses between 
192.168.1.200 and .229 and the Metis IP address assigned was 
192.168.1.104 (or other .10x addresses), and [2] by reviewing the 
WireShark output..

If I disconnected the Router from the switch that had my Linux 
mailserver, Metis, and my Windows PC-with-Wireshark, then the Linux DHCP 
server would also successfully give Metis an IP address [in the .200 to 
.229 range].  But if both DHCP servers were available, the LinkSys 
Router would prevail.

I just pass this along as info to anyone who may be having trouble 
getting an IP address from their Linksys Router...not that you need to 
do so, since Metis will give itself an APIPA address if the DHCP 
assignment fails.

I have confirmed this behavior several times by turning off the DHCP 
server on the Linux box and again seeing the LinkSys Router fail to 
assign an IP address to Metis, and turning back on the DHCP server on 
the Linux box and having the LinkSys Router then again suceed in giving 
an IP address to Metis.

I have also duplicated the behavior with 2 separate Metis cards.  Both 
have the original firmware; I have not attempted to load new firmware.

I got the same behavior whether I connected Metis to the switch to which 
the LinkSys Router is connected, or to the branch switch that has my 
Windows PC and the Linux mailserver.

Interestingly, the LinkSys Router seems to do fine assigning IP 
addresses to the PCs on the network that don't have fixed IP addresses, 
even in the absence of the Linux box DHCP server.  So this is not a 
general problem with my LinkSys Router's DHCP function.

I do not have an explanation for this behavior, and this is definitely 
not a complaint or even a bug report, but just information for anyone 
who may have noticed that their LinkSys Router wouldn't successfully 
give Metis an IP address.  It really doesn't matter to me if my Metis 
has the IP 192.168.1.x or 169.254.x.x. So I am quite happy with things 
as they are  ;)

-- 
73,

W3SZ
Roger Rehr
http://www.nitehawk.com/w3sz