Can't resolve network names with PPP/DUN connections

[Rick Stevens]

On Thu, 2006-12-07 at 15:51 -0800, Mark A. Miller wrote:
> I have an Asus Z71A laptop running FC5 and WinXP.  I don't have any
> problems with networking when I use Ethernet or 802.11g in either OS.
> 
> I am having problems with name resolution when I use my cell phone as a
> networking device, but only when I boot into FC6.  Using the cell phone
> as a modem works well in Windows, and even with the SLAX live CD
> distro.  But in my Fedora environment, name resolution is so slow that
> I can only ping/ssh/web browse to numerical addresses, for all
> practical purposes.
> 
> I am using software called USB Modem, from Mobile Stream, on my phone. 
> I have followed their suggestions (see below), except I couldn't find a
> /etc/ppp/resolve.conf, so I do this instead:
> 
> # cat /etc/ppp/resolve.conf > /etc/resolve.conf
> 
> Can anyone suggest how I can trouble shoot this situation?

First, it should be "resolv.conf" (no "e").

Second, if you don't have an /etc/ppp/resolv.conf, why are you copying
it to /etc/resolv.conf?  At best it'll fail.  At worst, it will null out
the /etc/resolv.conf file.  Either way, it's bad.

Your /etc/resolv.conf (at a minimum) should contain the IP address of
your DNS server(s), e.g.

	nameserver aaa.bbb.ccc.ddd
	nameserver eee.fff.ggg.hhh

You can specify up to 3 "nameserver" entries in the current Linux
implementation.  If your default route is correct (see below), then you
can probably use your normal ISP's DNS (the ones you use when running
hard-wired or over 802.11g) and you really don't need to replace your
/etc/resolv.conf with a special one for PPP--unless your ISP restricts
access to their DNS to stuff coming over their PPP links (broadband,
cable modem, DSL, etc.).  Some ISPs do that.

Third, verify that the default route got set.  Use "netstat -rn" as root
and look for a line that looks something like:

	0.0.0.0   aaa.bbb.ccc.ddd     0.0.0.0   UG     0 0      0 ppp0

The "aaa.bbb.ccc.ddd" will be the default gateway's IP address.  In your
case, it's probably OK since you can browse via IP addresses.  This also
means that your regular DNS servers should be available for use, since
they're checked via IP address.  If you can ping them or do a "dig
@ip-of-dns-server www.fedora.org" and get a reply, then you're good to
go.

> ---  USB Modem readme   ---
> 
> This is a quick USB Modem for Linux usage guide.
> 
> See the USBModem_UG.pdf for the full documentation.
> 
> 
> 
> [Requirements]
> 
> Linux distribution with CDC ACM class driver (either compiled in the
> 
> kernel or as a module named cdc-acm.ko) and a reasonably recent pppd
> 
> version.
> 
> 
> 
> These instructions were tested on a SLAX Live CD distribution and
> 
> should work on any modern distribution as well.
> 
> 
> 
> 
> 
> [Installation and Configuration]
> 
> Obtain the following connection parameters from the mobile operator:
> 
> user name, password. For GSM networks the APN is also required.
> 
> 
> 
> Copy either ppp-script-edge-template (for GSM GPRS/EDGE networks)
> 
> or ppp-script-evdo-template (for CDMA 1xRTT or EVDO networks) file
> 
> from the USB Modem distribution to /etc/ppp/peers/ppp-script-treo
> 
> (you may need to create the path by hand), replacing the USERNAME
> 
> and APN (for GSM only) words with the correct values.
> 
> 
> 
> Also add the user name and password line from the pap-secrets-template
> 
> to the /etc/ppp/pap-secrets file, replacing the USERNAME and PASSWORD
> 
> words with the correct values.
> 
> 
> 
> See the mts folder for the complete example scripts tuned for the
> 
> MTS GSM operator.
> 
> 
> 
> 
> 
> [Connecting the Treo to Linux PC]
> 
> Connect Treo with Linux PC using a USB cable and enable the USB Modem
> 
> mode. Linux will recognize the USB device and load the CDC ACM class
> 
> driver.
> 
> 
> 
> Type as root:
> 
> 
> 
> 	bash-2.05# pppd /dev/ttyACM0 call ppp-script-treo
> 
> 
> 
> It will print how the connection setup is performed. If it was
> 
> successful a new network interface will be created (usually ppp0).
> 
> The only thing left is to copy the content of /etc/ppp/resolv.conf
> 
> to system-wide /etc/resolv.conf for proper name resolution. E.g.:
> 
> 
> 
> 	bash-2.05# cat /etc/ppp/resolve.conf > /etc/resolve.conf
> 
> 
> 
> The connection setup is done.
> 
> 
> 
> To disconnect, kill the pppd process:
> 
> 
> 
> 	bash-2.05# kill <pppd_process_pid>
> 
> 
> ---   USB Modem PPP script   ---
> 
> 921600
> connect '/usr/sbin/chat -s -v  "" "AT&F0E0V1S0=0"  OK ATD#777  CONNECT'
> debug
> updetach
> crtscts
> noipdefault
> novj
> lcp-echo-failure 0
> nobsdcomp
> novjccomp
> nopcomp
> noaccomp
> user USERNAME
> modem
> usepeerdns
> defaultroute
> connect-delay 5000
> 
> 
> ---   ---   ---   ---   ---   ---   ---   ---
> 
> Mark A. Miller
> 
> 
>  
> ____________________________________________________________________________________
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> 
----------------------------------------------------------------------
- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
- Grabel's Law: 2 is not equal to 3--not even for large values of 2. -
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