Relationships for MAC Addresses

[Alan Prochaska]

The CI Class Manager shows both parent and child suggested relationships for IP Address, but only child suggested relationship for MAC Address.  Why?  A physical Ci (ie. one which has an associated asset) will likely have both a MAC and IP Address.  I'd expect those CIs to have an Owns relationship to both MAC Address and IP Address.  See the attachments.  The IP Address map is rather large, and I couldn't figure out how to paste it inline.

IP Address and MAC Address fields are OOB in the cmdb_ci table.  MAC address does not appear in alm_hardware

SN Docs say MAC Addr should be specified only on Network Adapter, not on Server.  Ok, but we're not instantiating Network Adapter so the MAC Addr gets specified on the parent (eg. Server, Computer, etc). 

Is it that a MAC Addr should be 1:1 with the device, so it would be stored in the attribute as a reference rather than a relationship?

Any guidance or experience re how you work with IP and MAC addresses would be helpful.  Thank you!

Alan Prochaska

[Alan Prochaska]

Hi JGates and Appli,

Thank you for the responses.

So I get it: we shouldn't relate devices to IP or MAC addresses.  We should relate devices to network adapters, which would in turn be related to IP or MAC addresses.  Unfortunately, our current implementation chose not to instantiate network adapters so we have the devices relating directly to the addresses.

My key takeaways are

a) A device could have multiple IP or MAC addresses, so relationships to those tables are appropriate.  Using a reference would limit it to one value, and putting the addr directly into the device attribute would be even worse.

b) The expected relationships are

<device> owns Network Adapter owns IP Address.

Would it be the same with MAC address?

<device> owns Network Adapter owns MAC Address

It's odd that Suggested Relationships in CI Class Manager only show a child relationship for MAC Address (uses Unique Certificate), but no parent relationship.

We're down-version on the CMDB CI Class Models app (1.37 released, 1.33 installed).  I've inquired about upgrading that.  1.33 is pre-Paris.  Don't know if updates to that would provide a suggested parent relationship for MAC Address.

In any case, until we start instantiating network adapters, then we should have relationships to IP and MAC Addresses, not references or stored values.

Comments?

[#3]

As mentioned originally, "I'm not sure what table you are looking at for the MAC Address attachment you posted, unless you renamed network adapter to mac address?"

There is no OOTB table called MAC Address.  That may be a custom table in the customer environment.  Network Adapter is the correct table for storing mac address.

The expected relationship you mention in point b are not correct either.  They are what I have originally posted:

Relationships

1) Parent Hardware Owns::Owned By Child Network Adapter

2) Parent Hardware Owns::Owned By Child IP Address

There are also the following reference fields:

1) cmdb_ci on network adapter

2) nic on ip address

The reference to cmdb_ci on network adapter doesn't limit it to a 1-1 relationship, it means that no network adapter can have more that 1 CI.  It doesn't restrict 1 CI from having more than 1 network adapter as the field is on network adapter.  The same thing pertains to the nic on ip address reference field.

[Appli]

Hi, thanks.

OOB, MAC address is an attribute of the network adapter CI class with no relationship set. For me, relating devices to MAC addresses may be tricky as always can be questioned - what network adapter does this MAC belongs on this device to - eth0, eth1, wlan0, etc. 

Hope it helps

[#5]

MAC address is also a field on network adapter.  Each network adapter would have it's MAC address field populated.