netconf settings

[Doug_3]

I posted a question a few days ago about net start and netconf. I queried the previous postings but not being a network eng or guru, I have additional questions. With respect to a N class with 2 nic's and apps that use udp and tcp on a WAN with quite a few subnets. Our network engineer modified the netconf file and now we are having difficulty with one app that is talking back to a service via tcp. We have had other changes so this may not be an issue.
But here is our current and old netconf file settings. Can someone comment if they look ok especially the BROADCAST_ADDRESS? We have 2 identical machines and what we are doing is swapping IP's so we can test Disaster Recovery as well as set up a box, upgrade, test, and then swap IP's almost unnoticably to the user.
Thanks in advance, Doug

NETCONF file from 2 years ago
INTERFACE_NAME[0]=lan0
IP_ADDRESS[0]=10.1.0.16
SUBNET_MASK[0]=255.255.255.0
BROADCAST_ADDRESS[0]=10.1.255.255
INTERFACE_STATE[0]=up
DHCP_ENABLE[0]=0

ROUTE_DESTINATION[0]=default
ROUTE_MASK[0]=""
ROUTE_GATEWAY[0]=10.1.0.1
ROUTE_COUNT[0]=1
ROUTE_ARGS[0]=""

RARP=0

IP_ADDRESS[1]=10.1.0.14
SUBNET_MASK[1]=255.255.255.0
INTERFACE_NAME[1]=lan1
BROADCAST_ADDRESS[1]=10.1.255.255
INTERFACE_STATE[1]=up
DHCP_ENABLE[1]=0
IP_ADDRESS[2]=10.1.0.16
SUBNET_MASK[2]=255.255.255.0
INTERFACE_NAME[2]=lan1:1
BROADCAST_ADDRESS[2]=10.1.255.255
INTERFACE_STATE[2]=up


netconf new from December 2003
INTERFACE_NAME[0]=lan0
#IP_ADDRESS[0]=10.1.0.16
IP_ADDRESS[0]=206.193.1.131
SUBNET_MASK[0]=255.255.255.0
#BROADCAST_ADDRESS[0]=10.1.255.255
BROADCAST_ADDRESS[0]=206.193.1.255
INTERFACE_STATE[0]=up
DHCP_ENABLE[0]=0

ROUTE_DESTINATION[0]=default
ROUTE_MASK[0]=""
#ROUTE_GATEWAY[0]=10.1.0.1
ROUTE_GATEWAY[0]="206.193.1.1"
ROUTE_COUNT[0]=1
ROUTE_ARGS[0]=""

#IP_ADDRESS[1]=10.1.0.14
IP_ADDRESS[1]=206.193.1.132
SUBNET_MASK[1]=255.255.255.0
INTERFACE_NAME[1]=lan1
#BROADCAST_ADDRESS[1]=10.1.255.255
BROADCAST_ADDRESS[1]=206.193.1.255
INTERFACE_STATE[1]=up
DHCP_ENABLE[1]=0
#IP_ADDRESS[2]=10.1.0.16
#IP_ADDRESS[2]=206.193.1.131
#SUBNET_MASK[2]=255.255.255.0
#INTERFACE_NAME[2]=lan1:1
#BROADCAST_ADDRESS[2]=10.1.255.255
#BROADCAST_ADDRESS[2]=206.193.1.255
#INTERFACE_STATE[2]=up
#DHCP_ENABLE[2]=0

[Steven E. Protter · Accepted solution]

You let your network engineer modify netconf?

Can not have two NIC's on the same network/subnet with HP-UX.

You have two different interfaces with subnest mask 255.255.255.0 Can't do that.

It is best to test the configuration with ifconfig commands first before modifyiing the permanent network configuration of your box.

This will let you see errors in configurations instead of having to read netconf and try and figure it out.

I would restore netconf, restart the server and then test the recommended changes one at a time with ifconfig and route add commands. Then you can take a specific error to your network guy.

Note there can only be one copy of netconf in /etc/rc.config.d/ directory

If there are two they will BOTH be processed. Keep backups elsewhere.

I have looked at your configuration and see you are not consistent with using double quotes. You should be consisten. Also an invisible character in the wrong place can lead to trouble.

The real issue though appears to be an unsupported configuration.

Remember also you can not with HP-UX have two NIC cards on the same network. Microsoft supports this, as does Linux HP-UX does not.

[Patrick Wallek]

In your old netconf file your broadcast addresses are incorrect. They are correct in your new file though. I don't see anything odd in your new netconf file. It all looks fairly normal and straightforward to me.

[Patrick Wallek]

Steven is right! Having 2 NICs in the same subnet is not supported.

I don't see a problem, however, of having 2 class C subnets (subnet mask 255.255.255.0) as long as they are different networks (206.193.1 on 1 NIC and 206.193.2 on the other for example).

We run 2 different class C networks on our machines without a problem (170.7.2 and 170.7.47 both with 255.255.255.0 subnet mask).

[Jeff Schussele]

Hi Doug,

Wow - does that mean if you know IOS you'd be allowed to log on to their routers & make changes? Let them deal with the router & you deal with the OS. The right tool for the job I say & that includes the person wielding it.

Now to the netconf file. Did the network dude create that new one? You're going to have trouble with it because you have *both* NICS on the same subnet. Not supported because traffic can come in one NIC & be sent out the other or vice-versa. IF you need 2 IPs on the same subnet set one of them up as a virtual - i.e.
lan0 = 206.193.1.131
lan0:1 = 206.193.1.132

My 2 cents,
Jeff

[Jeff Schussele]

Or if you need 2 NICs for the bandwidth increase then purchase & use APA (Auto Port Aggregation).

Rgds,
Jeff

[Brian Hackley]

Doug,

You didn't say exactly what the symptoms of the problem the application was showing.

Secondly never manually fill in the BROADCAST ADDRESS. We know set_parms and SAM like to do that, but there is no earthly reason to add another field to be changed when reconfiguring a system. The system will create the correct broadcast address unless specified with the ifconfig command "broadcast" option.

It has been pointed out by other respondants to your posting that you are using 2 IP's on the same subnet. Are you sure you want to do this?
It does work, but we don't recommend it. See ITRC Doc # UTRANKBRC00011759 for more details.

Good luck with your DRP strategy, I hope this helps a little,

-> Brian Hackley