DNS problem with pppd dialup /w cellphone

Juzzam · 02-25-2006, 06:37 PM

I'm trying to setup my RHEL 4 laptop to dial-up using my cellphone (Nokia 7610). The phone shows up as a standard serial modem on /dev/ttyACM0 when I plug it in via USB.

When I try to dial-in with pppd I think it connects, because it gives me an IP Address and DNS:

Code:

local  IP address 10.178.162.86
remote IP address 10.6.6.6
primary   DNS address 66.94.9.120
secondary DNS address 66.94.25.120

I can ping IP addresses, but I can't ping domain names. For example, I cannot ping yahoo.com, but I can ping its real IP address (216.109.112.135). When I do a ./route I get the following:

Code:

Kernel IP routing table
Destination	Gateway         Genmask         Flags Metric Ref    Use Iface
10.6.6.6        *               255.255.255.255 UH    0      0        0 ppp0
default         10.6.6.6        0.0.0.0         UG    0      0        0 ppp0

Notice that it has 10.6.6.6 as the gateway. Shouldn't it be 66.94.9.120 - the primary DNS listed by pppd? I *can* ping the primary DNS IP (66.94.9.120).

Is there linux networking command I need to run to correct the DNS?

I really appreciate the help - I've been wrestling with this for weeks =(

More Details:
I know this can work because it works great under windows. In windows I go through the regular dialup settings except I leave the user/password blank, dial *99#, and put the following in as an init string (in advanced modem properties):
at+cgdcont=1,"IP","internet2.voicestream.com"

I know very little about pppd. I got the scripts I'm using from here: linuxdevcenter.com/pub/a/linux/2004/02/05/linux_cellular.html

To try to connect, I run /usr/sbin/pppd call tmobile

My pppd script located at /etc/ppp/peers/tmobile is as follows:

Code:

/dev/ttyACM0 
115200
defaultroute  # use the cellular network for the default route
usepeerdns    # use the DNS servers from the remote network
nodetach      # keep pppd in the foreground
crtscts       # hardware flow control
lock          # lock the serial port
noauth        # don't expect the modem to authenticate itself
local         # don't use Carrier Detect or Data Terminal Ready
debug 
connect    "/usr/sbin/chat -v -f /etc/chatscripts/tmobile-connect"

My chat script located at /etc/chatscripts/tmobile-connect is as follows:

Code:

TIMEOUT 10
ABORT   'BUSY'
ABORT   'NO ANSWER'
ABORT   'ERROR'
SAY     'Starting GPRS connect script\n'

# Get the modem's attention and reset it.
""      'ATZ'

# E0=No echo, V1=English result codes
OK      'ATE0V1'

# Set Access Point Name (APN)
SAY     'Setting APN\n'
OK      'AT+CGDCONT=1,"IP","internet2.voicestream.com"'

# Dial the number
ABORT   'NO CARRIER'
SAY     'Dialing...\n'
OK      'ATD*99#'
CONNECT ''

Finally, the output is as follows:

Code:

[root@bobpete sbin]# ./pppd call tmobile
Starting GPRS connect script
Setting APN
Dialing...
Serial connection established.
using channel 6
Using interface ppp0
Connect: ppp0 <--> /dev/ttyACM0
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x89e96abe> <pcomp> <accomp>]
rcvd [LCP ConfRej id=0x1 <magic 0x89e96abe> <pcomp> <accomp>]
sent [LCP ConfReq id=0x2 <asyncmap 0x0>]
rcvd [LCP ConfAck id=0x2 <asyncmap 0x0>]
rcvd [LCP ConfReq id=0x0 <auth pap> <mru 1500> <asyncmap 0xa0000>]
No auth is possible
sent [LCP ConfRej id=0x0 <auth pap>]
rcvd [LCP ConfReq id=0x1 <mru 1500> <asyncmap 0xa0000>]
sent [LCP ConfAck id=0x1 <mru 1500> <asyncmap 0xa0000>]
sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15>]
sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns3 0.0.0.0>]
rcvd [IPCP ConfReq id=0x0 <addr 10.6.6.6>]
sent [IPCP ConfAck id=0x0 <addr 10.6.6.6>]
rcvd [LCP ProtRej id=0x0 80 fd 01 01 00 0c 1a 04 78 00 18 04 78 00]
rcvd [IPCP ConfRej id=0x1 <compress VJ 0f 01>]
sent [IPCP ConfReq id=0x2 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns3 0.0.0.0>]
rcvd [IPCP ConfNak id=0x2 <addr 10.172.130.252> <ms-dns1 66.94.9.120> <ms-dns3 66.94.25.120>]
sent [IPCP ConfReq id=0x3 <addr 10.172.130.252> <ms-dns1 66.94.9.120> <ms-dns3 66.94.25.120>]
rcvd [IPCP ConfAck id=0x3 <addr 10.172.130.252> <ms-dns1 66.94.9.120> <ms-dns3 66.94.25.120>]
not replacing existing default route to eth0 [192.168.0.1]
local  IP address 10.172.130.252
remote IP address 10.6.6.6
primary   DNS address 66.94.9.120
secondary DNS address 66.94.25.120

Juzzam · 02-25-2006, 10:59 PM

It's working - I'm writing this reply via my cellphone connection. All I had to do was edit /etc/resolve.conf and replace nameserver 192.168.0.1 with nameserver 66.94.9.120 (Primary DNS given by pppd).

Anyone know of a way to script it so the resolve.conf file gets updated automatically?