[sane-devel] Newly installed cable modem caused loss of wifi scanner connection

[Gene Heskett]

On Thursday 30 March 2017 00:31:31 Roger wrote:

> > On Wed, Mar 29, 2017 at 09:48:32PM -0400, guy wrote:
> >I'm trying to help a neighbor, I have basic user level knowledge of
> >Linux, he doesn't have any.
> >I installed Linux Mint 17 on his Dell Laptop and successfully
> > installed his wireless HP Deskjet 3520 Printer/scanner. The scanner
> > has worked well for about 4 months.  The other day his cable
> > provider installed a new router, I was able using CUPS to install
> > his printer but Simple Scan and Xsane do not see the scanner.  I
> > assumed its do to a change of IP address.  However, I cannot find
> > any facility for checking the IP configuration setting.
> >
> >I look forward to any suggestions in resolving this lack of
> > connectivity.
>
> This is another reason I deplore networked printers, if you change the
> default route (or replace the router), you'll need to change the
> printer's IP settings prior to instituting the changes with new router
> settings.  Some printers (and devices) do have a display you can
> navigate to change the IP address of the unit.
>
> Some units do not, requiring you to either set the unit's IP settings
> to either default (eg. DHCP if you're luck) or you'll need to
> reconnect to the printer with either the old router settings or by
> directly connecting the unit to the computer.  (The later, can be more
> difficult.)
>
> If the HP printer's IP address is 192.168.1.115 and you switched the
> default route from 192.168.1.1 to 192.168.2.1, you'll need to switch
> the printer's IP address to 192.168.2.115.  (Take note of a change of
> the second from last digit, denoting routing.)
>
> Following is a more brief example.
>
> Before:
> 192.168.1.115
> via route 192.168.1.1
>
> After should be:
> 192.168.2.115
> via route 192.168.2.1

And even better idea is to setup ones home network at 182.168.XX.ZZ.

Most important thing you can do is buy a router with enough flash memory 
so it can be reflashed with dd-wrt.

dd-wrt has been installed here for many years, on several different 
routers. I use /etc/hosts as the local dns lookup, and if that fails its 
handed off to the router. In over a decade, only one person has accessed 
this network and its machines, a friend I needed help from, and I had to 
give him the password. I have a brother printer with LAN access, and I 
can change its address from its own control panel, so its set in the 
same XX block, and two entries in the /etc/hosts file, one for its 
scanner, and a duplicate for the printer as its an MFC machine.

The web page in the sig is NAT'ed to this machine by the router, and nmap 
can't find any leaks in the sandbox I run apache2 in, but you can browse 
freely and download anything that interests you.

I don't run a firewall on any of these currently 7 machines, dd-wrt is my 
guard dog. These decent routers all have radios in them, but they cannot 
access my network thru the radio, only steal some of my bandwidth to the 
internet. And I only turn the radio on when one of my boys visits with 
one of these fawncy cell phones that needs a wifi.

Having control over who comes in, is a nice secure feeling, and you can't 
have that feeling with any router out of the box as all have NSA or 
similar backdoors. dd-wrt has no back doors you didn't create and know 
about.

I have 2 such routers, only one in service at any one time, 1st is a 
Buffalo NetFinity, the 2nd for emergency use is a netgear running at the 
Buffalo's MAC address by cloning, that so my internet address isn't 
changed by my ISP when I use the netgear.  It's also reflashed with 
dd-wrt.  But I've found the netgear is forgetfull, and needs a powerdown 
reboot about weekly to restore everything. 

An old farts 2 cents. Adjust for inflation since 1934.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>