Cisco Support Community
Community Member

IP Addressing on an IBM 3172

My knowledege of IBM networking is limited. Could you please help with the following query:

Does an IBM 3172 see its allocated IP address as consisting of 3-digits or does it see it as consisting of 2-digits???


We have an IBM 3172, which has been allocated an IP address, for example say

I have been asked if the 3172 will see the IP address as a 3-digit address or will it see it as a 2-digit address.

Thanks in advance for your help.


Re: IP Addressing on an IBM 3172

I do not quite understand your question. Where do you see the IP address? Do you mean the 3172 configuration, TCP/IP profile, or the actual IP packets?

Community Member

Re: IP Addressing on an IBM 3172

Thanks for your e-mail.

I have checked with the person posing the question...

It appears that we are talking about the channel address that the 3172 connects to the mainframe with, e.g. AA0, and NOT the IP address.

Let me know if this makes my initial query an clearer, or if you need any further details.




Re: IP Addressing on an IBM 3172


I do not have much experience on 3172. However, I try to use my experience in CIP. There are 2 parameters required for ESCON. Path and subchannel address. If you use bus and tag, the path is always 0100. Path can be pretty complicated if you have multiple LPARs and an ESCON director.

subchannel is a 2-digital number. I think that your co-worker is asking for this.

All 3712 documentation can be found in the following URL:

Community Member

Re: IP Addressing on an IBM 3172

Have a look at

Community Member

Re: IP Addressing on an IBM 3172

I guess you're refferring to Channel connectivity. You've got to review the 3172 ICP definition, the Mainframe IOCP definitions, IP stack, etc.


- ESCON or Parallel

- If ESCON, using a Director?

- Need multiple LPARS?

- IP addresses

- IOCP definition


- Path

- 3172 ICP

- Lan Adapter config.

- Physical adapters installed

- Lan Media

TheHOST CUA's are defined and used in pairs. The even number to receive on and the next address in-line to transmit on. For Example FE0, FE1. You have to match up all your path definitions (ICP Lan adapter, IOCP, IP stack, etc.).


CreatePlease to create content