Difference between revisions of "Connection and VPN Bonding"

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(Testing Modem with wvdial)
(Client)
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Replace 5555555555 with your devices phone number.  I cant remember what the no auth option is.  It was actually working with any number...so...
 
Replace 5555555555 with your devices phone number.  I cant remember what the no auth option is.  It was actually working with any number...so...
 +
 +
===ppd and chat scripts===
 +
We are going to use pppd to manage and connect to the modems.
 +
 +
I used the command:
 +
 +
pppd updetach defaultroute usepeerdns noipdefault debug noauth asyncmap 0 ipcp-accept-local ipcp-accept-remote modem crtscts  noauth connect '/usr/sbin/chat -t5 -v -e -E -f /etc/ppp/peers/vzw_chat' 100 460800 /dev/ttyUSB0
  
 
=Notes=
 
=Notes=

Revision as of 10:13, 27 February 2012

Objective

Perferablly bond multiple 3G modems together to create a stable faster connection. I am trying to aggregate 3 unstable connections into one.

Ideas

  • Bond 2-3 OpenVPN tun interfaces.
    • LAGG
    • Kernel Bonding
      • LACP (Stable connections, same BW)
  • Linux Advanced Routing & Traffic Control - http://lartc.org/

Notes

Custom Linux

I tested with debian.

Server Configuration

I used a Debian VPS because I wanted to route all my traffic out to the internet through the bond.

OpenVPN

su -
aptitude update
aptitude upgrade
aptitude install openvpn

tap configuration is a bit different then tun configuration. Since it works via layer two you do not need to worry about layer 3 stuff like IPs in the config file.

Setup a CA, Certs, ta.key: http://wiki.hackspherelabs.com/index.php?title=OpenVPN#Setup but here are some commands for reference:

mkdir /etc/openvpn/easy-rsa
cp /usr/share/doc/openvpn/examples/easy-rsa/2.0/* /etc/openvpn/easy-rsa
cd /etc/openvpn/easy-rsa/
source ./vars
./clean-all
./build-ca
./build-key-server servername
./build-dh
cd keys
openvpn --genkey --secret ta.key
cd ..
./build-key-pkcs12 clientx

You need some openvpn config files in /etc/openvpn/ and here is an example of a tap server openvpn config file:

Template error: are you trying to use the = sign? Visit Help:Template#Escape template-breaking characters for workarounds.
Template error: are you trying to use the = sign? Visit Help:Template#Escape template-breaking characters for workarounds.

You need a vpn server for each modem that you want to bond. You will need to configure a different port and ip for each one while also a different tap interface.

You need to stop and disable openvpn from starting because the bonding.sh script will call openvpn.

/etc/init.d/openvpn stop
update-rc.d openvpn disable

You also need the utilities that this script calls

aptitude install uml-utilities ifenslave
Template error: are you trying to use the = sign? Visit Help:Template#Escape template-breaking characters for workarounds.
Template error: are you trying to use the = sign? Visit Help:Template#Escape template-breaking characters for workarounds.

Take note of the 'modprobe bonding mode=0 miimon=100' line. I use zero because I would like to try and combine the BW of both modems. The bonding mode is important depending on what you would like to do:

Possible values are:

  • balance-rr or 0 - Round-robin policy: Transmit packets in sequential order from the first available slave through the last. This mode provides load balancing and fault tolerance.
  • active-backup or 1 - Active-backup policy: Only one slave in the bond is active. A different slave becomes active if, and only if, the active slave fails. The bond's MAC address is externally visible on only one port (network adapter) to avoid confusing the switch.
  • balance-xor or 2 - XOR policy: Transmit based on the selected transmit hash policy. The default policy is a simple ( {source} \oplus {destination} ) % n_{slaves} - Alternate transmit policies may be selected via the xmit_hash_policy option. This mode provides load balancing and fault tolerance.
  • broadcast or 3 - Broadcast policy: transmits everything on all slave interfaces. This mode provides fault tolerance.
  • 802.3ad or 4 - IEEE 802.3ad Dynamic link aggregation. Creates aggregation groups that share the same speed and duplex settings. Utilizes all slaves in the active aggregator according to the 802.3ad specification. (Need Switch Support)
  • balance-tlb or 5 - Adaptive transmit load balancing: channel bonding that does not require any special switch support. The outgoing traffic is distributed according to the current load (computed relative to the speed) on each slave. Incoming traffic is received by the current slave. If the receiving slave fails, another slave takes over the MAC address of the failed receiving slave. Need Switch Support)
  • balance-alb or 6 - Adaptive load balancing: includes balance-tlb plus receive load balancing (rlb) for IPV4 traffic, and does not require any special switch support. The receive load balancing is achieved by ARP negotiation.

More info here: http://www.linuxfoundation.org/collaborate/workgroups/networking/bonding

You will also want to cleanup the bonding script after exit or when you need to:

Template error: are you trying to use the = sign? Visit Help:Template#Escape template-breaking characters for workarounds.
Template error: are you trying to use the = sign? Visit Help:Template#Escape template-breaking characters for workarounds.

NAT Forwarding as Internet Gateway

The entire reason I wanted to do this was to forward internet traffic through multiple modems. So on my debian box:

nano /etc/sysctl.conf

Uncomment: #net.ipv4.ip_forward=1

echo 1 > /proc/sys/net/ipv4/ip_forward

You then can forward incoming traffic with:

iptables -t nat -A POSTROUTING -o bond0 -j MASQUERADE
nano iptables.nat.sh

An put the line in it.

Client

Configuring the modems, vpns, bonding, forwarding, to connect adn route to the vpn server.

USB Drive/Modem CD Rom Eject

I have some novatel wireless usb modems. They have built in mini sd card holders and emulated cdrom drives on them for drivers. To get them to work in linux or bsd you need to eject the drive.

The first step is to disble some settings for the usb devices in windows. You cannot get around it. I had to disable "Enable Removable Disk" and Enable CD-ROM Disk in my software card manager that I installed in windows. (VZAccess Manager)

You would think that disabling the drive would disable it all the way. It does not. You have to make the OS eject it on plugin.

The next step is to get the OS to eject the CD drive:

After you plug the device in edit /etc/udev/70-persistent-cd.rules find your device (Novatel_Mass_Storage) and add:

, RUN+="/usr/bin/eject %k"

You will have to do this for each of these type of modems.


Testing Modem with wvdial

I used wvdial to test the modem. It looks like pppd accepts .chat scripts too. Here is my wvdial conf script:

Template error: are you trying to use the = sign? Visit Help:Template#Escape template-breaking characters for workarounds.
Template error: are you trying to use the = sign? Visit Help:Template#Escape template-breaking characters for workarounds.

Replace 5555555555 with your devices phone number. I cant remember what the no auth option is. It was actually working with any number...so...

ppd and chat scripts

We are going to use pppd to manage and connect to the modems.

I used the command:

pppd updetach defaultroute usepeerdns noipdefault debug noauth asyncmap 0 ipcp-accept-local ipcp-accept-remote modem crtscts  noauth connect '/usr/sbin/chat -t5 -v -e -E -f /etc/ppp/peers/vzw_chat' 100 460800 /dev/ttyUSB0

Notes

pfSense

With the USB760 modem you need to eject the drive before it works.

cdcontrol -f /dev/cd0

This needs to be automated. This thread suggests a devd rule: http://forum.pfsense.org/index.php/topic,43285.0.html

bsd router/firewall/more

Notes

ZeroShell

Zeroshell is a Linux distribution for servers and embedded devices aimed at providing the main network services a LAN requires. It is available in the form of Live CD or Compact Flash image and you can configure and administer it using your web browser.

  • Says it supports VPN Bonding
  • 3G support (+It is linux)

Notes

udev/cdcontrol Creation