Serviceguard package for multiple subnets

[Michael Simone]

We're in the process of reorganizing our whole network from a single Class C subnet (192.xxx.100.0) to a "supernet" (192.xxx.100.0-192.xxx.103.0) by changing everyone's subnet mask to 255.255.252.0. This is to accomodate a new system we have going in next month, but for the interim, I still have a Serviceguard package on 2 Ns configured with 192.xxx.100.100, and a subnet setting of 192.xxx.100.0.

Do I have to do anything to the Serviceguard package to allow it to accept telnet connections from the new subnets (101,102,103), or is it just the mask on the individual hosts that matters? I'm unclear on whether the subnets configured in my SG scripts are for accepting connections, or monitoring connectivity.

Thanks for your help.

[Jeff Schussele]

Hi Michael,

No you do not have to do anything in MC/SG regarding telnet.
Connectivity is toggled on/off in the /etc/inetd.conf file & connectivity control is exercised in /var/adm/inetd.sec.
As long as NO changes will be made to either cluster member address-wise or mask-wise, then no changes will be necessary to MC/SG configuration.


Rgds,
Jeff

[Michael Simone]

I'm sorry, Jeff, I'm still a little confused. I will be changing the subnet masks on the two nodes that comprise my cluster (changing from 255.255.255.0 to 255.255.252.0). I know that individually, this would allow me to telnet to their individual IPs. But would I then be able to telnet to the cluster's IP from the new subnets (101,102,103), or would that require changing the SG scripts.

Thanks.

[Sridhar Bhaskarla]

Michael,

You do need to do changes to your service guard cluster if your subnet is numerically changed. Look at your package config and control files and you will find the subnet entries there. See if they need to change. If not, you don't need to. In this case, I don't think so.

-Sri

[Jeff Schussele]

Hi Michael,

Heartbeat subnetmask will depend on how you have implemented the Heartbeat.
If you have direct-connected the heartbeat on a LAN I/F deicated to MC/SG and have assigned a unique subnet - then NO you can leave it & it's subnet mask alone.
But if the hearbeat is connected into your network & assigned IPs by your network admins - them you may have to change the subnet mask. Consult with your network admins about this. Remember that network congestion/delays can cause lost heartbeats & unnecessary pkg switching. I personally prefer to use direct-connect heartbeats for this reason.

As to the cluster, or virtual, IP - I don't think so. Can you telnet to it now from outside the subnet?
If you can I doubt you'll have to change.
Again, consult with the network admins. They should be able to guide you in this respect.

Rgds,
Jeff