DTC48 - change IP address

[Fred Martin_1]

I'm creating a subnet and so, need to give a new IP address, subnet mask and gateway to an old DTC48.

I remember that it was a pain to move the dtcmanager software from one server to another, so I wanted to check to see if there is anything I need to worry about for just changing the IP and subnet for a DTC.

So far, it looks like this is what I need to do, beyond my own DNS/routing changes:

1. modify /etc/ddfa/dp
2. dtcconfig, configure LAN address
3. restart ddfa

I've never configured a gateway or subnet mask in dtcconfig, since the server running the ocd's and rbootd has always been on the same subnet. Now it won't be.

I guess I'll need to do that now using dtcconfig.

Anything else?

[Rodney Hills]

If the DTC is another subnet, how will its rbootd request get to your host?

We subnetted our plant heavily using Cisco VLANS, but I made sure the DTCs were all on the same VLAN with our HPUX host.

Rod Hills

[Fred Martin_1]

In dtcconfig, if I modify the DTC in question and choose board=C, then 'Config DNS/IP' there is:

IP Routing
Default IP Router Address...
Subnet Mask...

I was rather hoping that if I put the subnet's local gateway in there, it would use that to forward the request on.

Am I mistaken about that? There are no values in there now.

[Fred Martin_1]

I just found this in the manual "Using the HP DTC manager/UX" ...

Default IP Router Address:
Enter the address of the default router. The router routes outbound packets for destinations which are not part of the local subnet.

That seems clear enough. As long as it applies to the device while it's booting, i.e. if I need dtcmanager running on each subnet I'm out of luck, I only have the one unix box.

[Rodney Hills]

As I understand it, rbootd uses a low level network protocol and it is not routable.

The routing definition in dtcconfig is used so that when a terminal signs on and a telnet session is initiated, it can connect to hosts on other subnets.

Their use to be a PC software product that could manage the DTC's across subnets instead of using hpux host based management.

Rod Hills

[Fred Martin_1]

Blast. Well, if true that certainly puts a damper on things.

I use Vanguard routers, which apparently can proxy a DCHP request. There's a possibility that they can pass on rbootd as well. I'll be contacting the vendor.

If not, I might just have to use another terminal server that isn't managed from a single point, the way HP's old DTCs are.

[Fred Martin_1]

proxy a DCHP request = proxy a DHCP request

[A. Clay Stephenson · Accepted solution]

Normally bootp packets don't route so a bootp server per subnet is good practice; however bootp/dhcp can be made to work defining "ip helper address"'s in the routers.

[Fred Martin_1]

Well according to man pages on rbootd, where 'same subnet' and 'local network' are mentioned, I'm thinking Rodney is right, the DTCs will only work on the same subnet as a server running rbootd.

I'd hate to have to replace these old DTC48s with newer terminal servers that don't require a boot protocol. Especially since they'll run into the 22nd century as long as you say nice things about them in their presence.

[Fred Martin_1]

Just spoke with HP directly, rbootd is not routable. I was told that some of their DTCs (DTC16rx for example) use tftpd instead of rbootd, which solves the subnetting issue.