Subnetting with MC-ServiceGuard

[Angel_17]

First of all, thanks for reading my question.

I want to install two nodes on a subnet which mask is 255.255.255.192
One node have 192.165.50.51 and the other 192.165.50.52, so the subnet bits are 00 (thinking that mask 255.255.255.0 is for the net, and 255.255.255.192 have two more bits for the subnet).

The command cmmodnet only accept ip and subnet (not mask). This is ised for assigning an IP to a packet.

In my example, I think there is an ambiguity: If the mask were 255.255.255.0 the values of cmmodnet were the same as if the mask was 255.255.255.192 (this is because my subnet number is 00; if my subnet was 10 for example there wasn't ambiguity)

My question is, does cmmodnet support masks different form A, B or C classes ?

Thanks four your comments,
-Angel R-

[G. Vrijhoeven]

Hi Angel,

I am also qurious about the answer to your question. The only thing i can tell you is that i have the same experience and what i assume.
In a package config file you specify the subnet. In the control file you specify the ipadress and the subnet. With both you should be able to figure out the subnet mask. But the cmmodnet command is issued with:
cmmodnet -a -i
If the subnet is not active on the cluster the command fails since the same subnet is not available if the ip-range is not the first range.

I hope s.o. can give you an answer since i did not find a document that says it is/ is not supported.

Regards,

Gideon

[V.Tamilvanan]

Hi Angel,

Yes.cmmodnet supports masks different from A,B or C classes.
What I believe is if suppose you have configured a Lancard locally (which is not related with cluster package) with 255.255.255.192 subnetmask and configure your package with ip 192.165.50.51 and 192.165.50.0 subnet your subnet mask for package will be same as your local lan card's(255.255.255.192).

If you don't have any lan configured with 255.255.255.192 subnet locally in your system your package will be assigned with 255.255.255.0 subnetmask which is default.

May be you can check and confirm it.

My systems are configured with classless ip address for packages.

[Bernhard Mueller]

Tamil and Gideon,

your assumptions are correct. The subnet mask for the package IP is read from the interface into that net at the time cmapplyconf is issued.

If you later change the subnet mask you will have to re-run cmapplyconf to reflect that change or the subnet mask on the interface will be cahnged back to the old one once you start the package (in the same subnet).

If you do not have an interface into a subnet and want to start a package with an IP in that range you get:

cmmodnet : Subnet 10.11.4.0 is not a configured subnet.
cmmodnet : Use the "netstat -in" command to list the configured subnets.
ERROR: Failed to add IP 10.11.4.71 to subnet 10.11.4.0
ERROR: Function add_ip_address
ERROR: Failed to add IP address to subnet


Regards,
Bernhard

[Angel_17]

Thanks to all of you.

As Gideon says, It should be nice to see an HP document telling what Bernhard confirms.

Tamil, the stationary IP's of the two nodes are these:
node1# ifconfig lan0
lan0: flags=843
inet 192.165.50.51 netmask ffffffc0 broadcast 192.165.50.63

node2# ifconfig lan0
lan0: flags=843
inet 192.165.50.52 netmask ffffffc0 broadcast 192.165.50.63

In the packet's control script I'll use this:
IP[0]="192.165.50.53"
SUBNET[0]="192.165.50.0"

If I haven't misunderstood, the packet will use mask ff.ff.ff.c0 as that is the lan0's configured netmask.



Thanks,
-Angel R-

[V.Tamilvanan · Accepted solution]

Hi Angel,
YES. the package will use mask ff.ff.ff.c0 as that is the lan0's configured netmask.
No doubt at all. As my package configuration runs with mask 255.255.248.0 without any problem

[Steven E. Protter]

This document might be helpful.
http://docs.hp.com/hpux/pdf/B2355-90787docs.pdf

As would a more general doc on subnetting.

SEP