HACL-HP

[Ludovic Derlyn]

Hi,

Who explain me how mc service guard detect that lan is down ?
What is method to detect it ?
(linkloop, ping...)
It's seems that used protocol is hacl-hp...
lan will be switched than is up ?
communication between card to card or submit a packet into network ?

regards

L-DERLYN

[John Bigg · Accepted solution]

Serviceguard uses link level communications to check the state of the lan. No checking is done at the IP level since the purpose of this is to check that the cards themselves are working. It is similar to linkloop but it is NOT linkloop and uses it's own link level communications using dlpi.

At the Serviceguard polling interval one cmcld thread polls lan cards locally and remotely depending on the physical configuration. If a poll returns an error the lan is marked down immediately. If no errors are detected the lan card statistics are checked. If the statistics do not increase, i.e. no traffic is sent or received then again the lan is marked down. This latter functionality is affected by the NETWORK_FAILURE_DETECTION parameter but simplistiocally this is how it works.

The more recent manuals describe this quite well. See the section at http://docs.hp.com/en/B3936-90100/ch03s05.html#chddbefj for a good explanation of this.

[Ludovic Derlyn]

thanks a lot !