Stand-by lan card in Service Guard and traffic

[Roberto Volsa]

Hello,
my environnment is a 2 nodes cluster (srervice Guard); each node has two lan cards.
Lan1 is the production lan, lan5 is the stan-by lan. In GPM i see all the traffic going through lan1, but there are few packets per seconds (inbount but also outbound!) from lan5: i did'nt expected this.
Ifconfig lan5 gives me 0.0.0.0.
is it correct?

Thanks in advance

Roberto

[Duncan Edmonstone · Accepted solution]

Roberto,

I expect this is ServiceGuard ensuring that the interface can be accessed at the data link level.

This is from Chapter 4 of the 'Managing ServiceGuard' manual:

Network Polling Interval
The frequency at which the networks configured for MC/ServiceGuard are checked. In the ASCII cluster configuration file, this parameter is NETWORK_POLLING_INTERVAL.
Default is 2,000,000 microseconds in the ASCII file (2 seconds in SAM). Thus every 2 seconds, the network manager polls each network interface to make sure it can still send and receive information. Changing this value can affect how quickly a network failure is detected.
The minimum value is 1,000,000 (1 second). The maximum value recommended is 15 seconds, and the maximum value supported is 30 seconds.


HTH

Duncan

[melvyn burnard]

Yes this is correct.
Your cmcld process is ensuring that the networks are healthy by polling out and in on all the networks on both nodes, so you will see small amounts of traffic appearing. This is one of hte ways cmcld detects an issue with the network if it sees no incoming traffic over a period of time.
As for the ip address, that is standrad for an unconfigured lan used as a standby.
If you do netstat -in you will see it is marked wiht an * showing it is unconfigured.
Also if you halt the cluster and this is HP-UX 11.x, you will find netstat -in will no longer show that lan!

HTH