T01: Using 802.1q VLAN's on Linux

The vlan tools (user mode utilities) should already be present on the Linux host (vconfig). On GNU/Debian they may be installed with "apt-get install vlan".

Setting up the VLAN interfaces (as root):

# modprobe 8021q

You may skip the line above if your kernel was compiled with 802.1q and not as module.

Let's add two VLAN interfaces based on eth4 and having the id's 100 and 101:

# vconfig add eth4 100 # vconfig add eth4 101

The VLAN interfaces may now be referenced from BalanceNG as eth4.100 and eth4.101 like this (starting another BalanceNG instance for testing):

# bng start 10 BalanceNG: starting up instance 10 ... # bng control 10 BalanceNG: connected to instance 10 PID 6425 bng# hostname "vlan-test" vlan-test# interface eth4.100 interface eth4.100 successfully attached vlan-test# interface eth4.101 interface eth4.101 successfully attached vlan-test# show conf // configuration taken Sat Mar 10 10:44:27 2007 // BalanceNG 1.807 (created 2007/03/09) hostname vlan-test interface eth4.100 interface eth4.101 // end of configuration vlan-test#

T02: How to strip the FCS (Frame Check Sequence) on Solaris e1000g interfaces

On Solaris 10 e1000g interfaces (and possible others) it might happen that an unexpected FCS (Frame Check Sequence) is being received from the interface file descriptor. This is in turn causes packet drops on the outgoing side since the Ethernet MTU of 1514 bytes gets exceeded by those 4 Bytes for large packets.

Setting the parameter outmtu to 1514 as follows is a suitable workaround in this situation:

# bng control 10 BalanceNG: connected to instance 10 PID 6425 bng# set outmtu 1514 bng# save

T03: How to enable SNMP on Windows for CPU-load monitoring with ascript and snmpload.sh

The following steps are necessary on the Windows target server:

• Invoke the Control Panel.
• Double click the Add/Remove Programs icon.
• Select Add/Remove Windows Components (The Windows Component Wizard is displayed).
• Check the Management and Monitoring Tools box.
• Click the Details button.
• Check the SNMP box and click OK, then Next.
• Additionally Port 161 for UDP needs to be added as an exeption at the Windows Firewall settings.
• You may have to reboot the machine.

For German Windows the click-path is as follows:

• Systemsteuerung ->
• Software ->
• Windows-Komponenten hinzufügen und entfernen ->
• Verwaltungs und Überwachungsprogramme ->
• Details ->
• SNMP.

The snmpload.sh source code is as follows:

#/bin/sh VALUES=`snmpwalk -v1 -c public -O qv $1 .1.3.6.1.2.1.25.3.3.1.2 2>/dev/null` if [ "$?" != "0" ] then echo 101 exit 0 fi SUM=0 COUNT=0 for VALUE in $VALUES do COUNT=`expr $COUNT + 1` SUM=`expr $SUM + $VALUE` done if [ "$COUNT" = 0 ] then echo 101 exit 0 else RESULT=`expr $SUM / $COUNT` RESULT=`expr $RESULT + 1` echo $RESULT exit 0 fi

T04: BalanceNG upgrade procedure for a dual node HA setup

The upgrade procedure consists of the following steps:

• Shutdown of the current VRRP backup ("bng stop")
• Upgrade of the VRRP backup node with the new BalanceNG release (either by replacement of binary or package reinstall)
• Restart of BalanceNG on the VRRP backup node ("bng start")
• Shutdown of the current VRRP master ("bng stop"), the already upgraded backup takes over and becomes the new master
• Upgrade BalanceNG on the former master (either by replacement of binary or package reinstall)
• Restart of BalanceNG on the former VRRP master ("bng start"), the node becomes the new backup (if VRRP priority != 255)
• ... done !

T05: Installing BalanceNG from the Thomas-Krenn.AG Debian Repository

As an alternative, you may benefit from the Thomas-Krenn.AG Debian Repository in order to install and upgrade BalanceNG.

Permission is explicitly granted by Thomas.Krenn.AG for all BalanceNG customers (the Thomas-Krenn Load-Balancer TKLB is already preconfigured in exactly the same way).

The following lines need to be added to /etc/apt/sources.list on Ubuntu or Debian systems first:

# Thomas-Krenn.AG Debian Repository deb http://debian.tk-dns.de/ etch tks

Then, the gpg key needs to be installed as follows (as root):

wget debian.tk-dns.de/gpgkey.gpg -O - | apt-key add -

Afterwards, BalanceNG may be installed as follows:

# apt-get update # apt-get install balanceng