HP APA Auto Port Aggregation

Friends,

So here I am once again with notes from another wonderful product from Hewlett-Packard. This product can be used to trunk two ports [ load balancing ] OR to have a fail over adapter. Similar products are available from Solaris and AIX as well. They are named IPMP and Ether-Channel respectively. I have not worked on IPMP but Ether-Channel.

For those who have never heard of such a product, This product will offer load balancing OR fail over for Ethernet adapters running TCP/IP. i.e. It can be used to run a single IP address over two Ethernet interfaces connected to two different switch ports ( to get 2*bandwidth) AND to run a single ip address active / passive mode.

Here I am going to discuss about the fail over scenario.

Requirement :-

lan0 and lan1 on this hpux system has been connected to two different switches. The switch ports are configured to be on the same VLAN. lan0 runs the ip address primarily and in case lan0, the cable or the switch port fail, the ip address should be re-located to lan1 w/o any clients knowing that such a change has happened.

Basically there are 2 configuration files for APA used for failover.

/etc/rc.config.d/hp_apaportconf
/etc/lanmon/lanconfig.ascii

1) . Configure the ipaddress on the primary adapter on the hpux system (/etc/rc.config.d/netconf )
2). Configure /etc/rc.config.d/hp_apaportconf as follows, This file should have all the adapters involved in the APA groups.

HP_APAPORT_INTERFACE_NAME[0]=lan0

HP_APAPORT_CONFIG_MODE[0]=LAN_MONITOR

HP_APAPORT_INTERFACE_NAME[1]=lan1

HP_APAPORT_CONFIG_MODE[1]=LAN_MONITOR

3) Configure /etc/lanmon/lanconfig.ascii as follows,

NODE_NAME # Replace this field with the real hostname of the system.

POLLING_INTERVAL 10000000

DEAD_COUNT 3

LM_RAPID_ARP off

LM_RAPID_ARP_INTERVAL 1000000

LM_RAPID_ARP_COUNT 10

FAILOVER_GROUP lan900 # First failover group (Public network)

STATIONARY_IP xx.xx.xx.xx

PRIMARY lan0 5

STANDBY lan4 3

... Phew ....

Stop and start the APA using the following commands.

/sbin/init.d/hplm stop

/sbin/init.d/hpapa stop

/sbin/init.d/hpapa start

/sbin/init.d/hplm start

Notes :

1) Before the configuration, test the ports are configured to the same speed and duplex settings ( lanadmin )
2) Try configuring ip address temporarily on each adapter and make sure that you can ping out to other hosts in the subnet. You may use linkloop command for this , but some switches don't support this command.

3) When APA is running, you will no longer see the physical adapter, It will show lan900 running the ip address.
4) If there is a stacked ip address on the primary adapter, That also will be moved during a failover. The limit for stacked ip addresses are 9.
5) Put your questions in comments and I will be more than willing to help you to my best possible level.

Regards, Kaps