In an effort to exercise new Linux capabilities, I have been mocking with the Bluez open source implementation of bluetooth for the past 2 months. I have managed to get a working NAT network over bluetooth connecting my laptop and desktop to the internet. Now, I can surf the internet from my laptop with no wires being attached. This article describes what is needed in order to get this done.
The following is assumed:
$ /usr/sbin/hciconfig -aIt should say something like UP RUNNING. Please note down the BD Address which is a 6 bytes address in the following format:
00:10:EC:71:F9:D6The response I get from the above command is
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hci0: Type: USB
BD Address: 00:10:EC:71:F9:D6 ACL MTU: 192:8 SCO MTU: 64:8
UP RUNNING PSCAN ISCAN AUTH ENCRYPT
RX bytes:512035 acl:3921 sco:0 events:17349 errors:0
TX bytes:5177521 acl:27340 sco:0 commands:25 errors:0
Features: 0xff 0xff 0x0f 0x00
Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
Link policy: HOLD SNIFF PARK
Link mode: SLAVE ACCEPT
Name: 'Grand Tux'
Class: 0x120104
Service Classes: Networking, Object Transfer
Device Class: Computer, Desktop workstation
HCI Ver: 1.1 (0x1) HCI Rev: 0x110 LMP Ver: 1.1 (0x1) LMP Subver: 0x110
Manufacturer: Cambridge Silicon Radio (10)
Note that the name of your Bluetooth device is controled by /etc/bluetooth/hcid.confchange the line
name "%h-%d";to
name "Grand Tux";You also have to setup a PIN access code to your system. For example, if you would like to set it to 1234 then do the following
$ echo "1234" > /etc/bluetooth/pin $ chmod 600 /etc/bluetooth/pinYou will need root access to apply the above changes. Moreover, restart the bluetooth service to re-confirm name and pin changes
$ /etc/init.d/bluetooth restart
$ /usr/sbin/brctlif not then get it from your fedora installation CDs/DVD.
$ /sbin/iptables -V $ /sbin/lsmod | grep ip_tables
You have to create a bnep0 configuration file on the server side. Here is what to do in /etc/sysconfig/network-scripts/ifcfg-bnep0
DEVICE=bnep0 ONBOOT=no BOOTPROTO=DHCPOn the Server Side Do:
$ /usr/sbin/brctl addbr pan0 $ /sbin/ifconfig pan0 10.0.0.1 $ /usr/sbin/brctl setfd pan0 0 $ /usr/sbin/brctl stp pan0 disable $ /sbin/modprobe bnep $ pand -s -M --role=NAPOn the Client Side Do:
$ /sbin/modprobe bnep $ pand -c 00:10:EC:71:F9:D6 $ /sbin/ifconfig bnep0 10.0.0.2 netmask 255.255.255.0 $ /sbin/route add default gw 10.0.0.1On the Server Side Do:
$ /usr/sbin/brctl addif pan0 bnep0 $ /sbin/ifconfig bnep0 0.0.0.0enable IP forwarding on the Server Side
$ echo "1" > /proc/sys/net/ipv4/ip_forward $ /sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE $ /sbin/iptables -A FORWARD -i pan0 -j ACCEPT $ /sbin/iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPTFor Internet Sharing on Server Side Do:
$ /sbin/iptables -t nat -A POSTROUTING -j MASQUERADE
Save your iptables setting so you don't have to re-do them again
$ /sbin/iptables-save
In addition, I also allow DHCP and DNS on the Server for total enjoyment. I have given my server and client both ethernet and bluetooth names. Bluetooth speed in sufficient for surfing the net but not for copying huge files for example. Here is a listing of what I got in my /etc/hosts file:
192.168.0.1 server.home.net server localhost.localdomain localhost 192.168.0.2 laptop.home.net laptop 10.0.0.1 btserver.home.net btserver 10.0.0.2 btclient.home.net btserverAdd the lines below to your /etc/named.conf . Note that you have to change ip_isp_dns1 and ip_isp_dns2 to your service provider DNS IP addresses. I use a dial-up connection to go online and this way, allows me to do DNS caching on my server side. Hence, it lowers DNS traffic from my side to my ISP.
forwarders { ip_isp_dns1; ip_isp_dns2; 192.168.0.1 };
allow-query { 192.168.0.0/24; 127.0.0.1/32; 10.0.0.2; 10.0.0.1 };
However, for DHCP, I have only allowed it for ethernet. This is what I have in my /etc/dhcpd.conf
default-lease-time 600;
max-lease-time 7200;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.0.255;
option routers 192.168.0.1;
option domain-name-servers 192.168.0.1;
option domain-name "home.net";
ddns-update-style ad-hoc;
option netbios-name-servers 192.168.0.1;
option netbios-dd-server 192.168.0.1;
option netbios-node-type 8;
option netbios-scope "";
subnet 192.168.0.0 netmask 255.255.255.0 {
range 192.168.0.2 192.168.0.254;
}
You could do the same thing for your bluetooth network by creating another subnet. Check the output below to see how different it is when I ping over ethernet and bluetooth from the client side
$ ping -c 2 btserver PING btserver.home.net (10.0.0.1) 56(84) bytes of data. 64 bytes from btserver.home.net (10.0.0.1): icmp_seq=0 ttl=64 time=36.3 ms 64 bytes from btserver.home.net (10.0.0.1): icmp_seq=1 ttl=64 time=23.9 ms --- btserver.home.net ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1000ms rtt min/avg/max/mdev = 23.962/30.170/36.378/6.208 ms, pipe 2 $ ping -c 2 server PING server.home.net (192.168.0.1) 56(84) bytes of data. 64 bytes from server.home.net (192.168.0.1): icmp_seq=0 ttl=64 time=0.236 ms 64 bytes from server.home.net (192.168.0.1): icmp_seq=1 ttl=64 time=0.269 ms --- server.home.net ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1007ms rtt min/avg/max/mdev = 0.236/0.252/0.269/0.022 ms, pipe 2