[TriLUG] Get a router now! - Re: newbie needs help with IP setup, part 2: static IP?

[Jeremy Portzer]

Tom Roche wrote:
> summary: the router/DHCP/DNS proposal sounds good! Just please lemme
> know if I can put that all on a LEAF box (or equivalent).
> 
> details:
> 
> <warning: ascii art/>
> 
> following up from
> http://www.trilug.org/pipermail/trilug/Week-of-Mon-20071203/052336.html
> note that our current physical network is like
> 
>                                           cat5-- backend
>                                          /
> --TWC cable-- Surfboard --cat5-- minihub
>                                          \
>                                           cat5-- lane
> 

Just remove the minihub and replace it with a (4 or 5 port) router, as 
previously said many times.  The consumer-level routers are ideal for 
this application.  Any that you can pick up at Intrex or Best Buy will 
do.  But the ideal one might be the WRT54GL because you could replace it 
with OpenWRT or similar advanced firmware in the future if you need. 
(Note:  the current WRT54Gs don't run the Linux firmware, and probably 
aren't found in stores; the WRT54GL is most likely to be found online.)

I disagree with Magnus that you need to be running your own DNS and DHCP 
servers for this.  That adds way too much un-needed complexity and 
requires a lot more skills.  You need to focus most likely on the basic 
network configuration, and the skills necessary to maintain/operate the 
POS system first.  There is no reason you need to be messing with all 
those config files he sent you.

Any router, even with the standard software, will allow the necessary 
configuration.  You can assign specific ('static' in the English sense) 
IP addresses to the backend and lane devices via DHCP, similar to what 
Magnus suggested.  Or you can just configure the router's DHCP server so 
that it assigns DHCP addresses in a different range from those being 
used for the POS devices.  With the latter setup, use actual static IP 
addresses on the POS machines.

Plus, with a router you'll be able to plug up your laptop (or get on via 
wireless) to the internal network for troubleshooting, with no problems 
at all.  Or configure the office PC that Quickbooks runs on, or whatever 
else is on the network.

None of this has anything to do with domain names.  You don't need a 
domain name for this configuration since you have no Internet services 
that will be used by the public.  So let your friend keep those domain 
names for something else!  For remote access, you can set up dynamic DNS 
through a site like dyndns.org.  Then you'll connect with SSH and/or 
VNC, as previously mentioned.   For even further ease of configuration, 
get one of the router models that automatically supports dyndns.org. 
But if you don't get one of those, configuration is still very easy by 
scheduling a simple script (probably on the "backend" server in your 
configuration).

Hope this helps,

Jeremy Portzer