topic Re: NIC MAC address change in Operating System - OpenVMS

NIC MAC address change

dennis cooper — Wed, 09 Dec 2009 16:39:29 GMT

In trying to move an application from Alpha to Itanium, I find I have to make the Itanium have the same MAC address as the Alpha as I cannot change the Siemens S5 PLC comms.

How can I change the MAC address on the Itanium?

I know I can't have 2 machines with the same MAC address, so I will be disconnecting one or the other as needed for tests...

Re: NIC MAC address change

Hoff — Wed, 09 Dec 2009 17:26:17 GMT

There's the hardware or physical Media Access Control (MAC) address, and that's somewhat more tough to change. There's the physical MAC address, and that can be changed from host-level software; DECnet sets the physical MAC, for instance. That's a $qio call.

As for changing the MAC address, the hardware or physical address can be a PROM. It's somewhat more difficult to change, particularly without the identity of the NIC. Some boxes can have it soft-loaded, some have a socketed PROM, and some can't be changed short of drastic measures.

Which NICs? That'll identify the soft-loaded or socketed stuff.

The best approach here is probably finding a MAC NAT box; basically, a box or switch that remaps the MAC addresses on the fly. That'll get you out of the current mess. There are fancy names for this MAC NAT; HP calls it "virtual connect" or some such, IIRC.

Re: NIC MAC address change

dennis cooper — Tue, 15 Dec 2009 15:00:39 GMT

OK.

It looks like the NICs are BCM5704.

The output from a 'show dev /full' and 'tcpip show int/full' is in the attached file.

Also included is info from
LANCP> sh conf
LANCP> sh dev/char

Thanks,
D

Re: NIC MAC address change

dennis cooper — Tue, 15 Dec 2009 15:53:51 GMT

My attach didn't!

Here's the info...

Here's what a show device tells me:

$ sh dev ewa0/full

Device EWA0:, device type BCM5704, is online, network device, error logging is
enabled, device is a template only.

Error count 2 Operations completed 0
Owner process "" Owner UIC [SYSTEM]
Owner process ID 00000000 Dev Prot S:RWPL,O:RWPL,G,W
Reference count 0 Default buffer size 512
Current preferred CPU Id 0 Fastpath 1
Current Interrupt CPU Id 0

Operating characteristics: Link up, Full duplex, Autonegotiation.

Speed (Mbits/sec) 100
Def. MAC addr 00-1C-C4-FB-DC-B3 Current MAC addr 00-1C-C4-FB-DC-B3
$ sh dev ewb0/full

Device EWB0:, device type BCM5704, is online, network device, error logging is
enabled, device is a template only.

Error count 2 Operations completed 0
Owner process "" Owner UIC [SYSTEM]
Owner process ID 00000000 Dev Prot S:RWPL,O:RWPL,G,W
Reference count 0 Default buffer size 512
Current preferred CPU Id 1 Fastpath 1
Current Interrupt CPU Id 1

Operating characteristics: Link up, Full duplex, Autonegotiation.

Speed (Mbits/sec) 100
Def. MAC addr 00-1C-C4-FB-DC-B2 Current MAC addr 00-1C-C4-FB-DC-B2

$ tcpip sh int/full
Interface: LO0
IP_Addr: 127.0.0.1 NETWRK: 255.0.0.0 BRDCST:
MTU: 4096
Flags: UP LOOP NOARP MCAST SMPX
RECEIVE SEND
Packets 0 0
Errors 0 0
Collisions: 0

Interface: WE0
IP_Addr: 200.200.200.25 NETWRK: 255.255.255.0 BRDCST: 200.200.200.255
Ethernet_Addr: 00-1C-C4-FB-DC-B3 MTU: 1500
Flags: UP BRDCST RUN MCAST SMPX
RECEIVE SEND
Packets 1681 30
Errors 0 0
Collisions: 0

Interface: WE1
IP_Addr: 120.102.41.213 NETWRK: 255.255.255.0 BRDCST: 120.102.41.255
Ethernet_Addr: 00-1C-C4-FB-DC-B2 MTU: 1500
Flags: UP BRDCST RUN MCAST SMPX
RECEIVE SEND
Packets 12692991 11065
Errors 0 0
Collisions: 0

LANCP> sh conf

CSNCGL LAN Configuration (15-DEC-2009 09:59:33.09):
Parent or
Device PrefCPU Medium/User Version Link Speed Duplex Auto BufSize MAC Address Type Description
------ ------- ----------- ------- ---- ----- ------ ---- ------- ---------------- ------------ -----------
EWA0 0 Ethernet X-78 Up 100 Full Yes 1500 00-1C-C4-FB-DC-B3 UTP Merl5704
EWB0 1 Ethernet X-78 Up 100 Full Yes 1500 00-1C-C4-FB-DC-B2 UTP Merl5704
LANCP> sh dev/char

CSNCGL Device Characteristics EWA0 (15-DEC-2009 10:00:13.00):
Value Characteristic
----- --------------
1500 Device buffer size
Normal Controller mode
External Internal loopback mode
00-1C-C4-FB-DC-B3 Default MAC address (Hardware LAN address)
Multicast address list
Ethernet Communication medium
FF-FF-FF-FF-FF-FF MAC address (Current LAN address)
128 Minimum receive buffers
256 Maximum receive buffers
Yes Full duplex enable
Yes Full duplex operational
00-1C-C4-FB-DC-B3 MAC address (Current LAN address)
TwistedPair Line media type
100 Line speed (mbps)
Enabled Auto-negotiation
Enabled Flow control
Disabled Jumbo frames
0 Failover priority
Link Up Link state

CSNCGL Device Characteristics EWB0 (15-DEC-2009 10:00:13.00):
Value Characteristic
----- --------------
1500 Device buffer size
Normal Controller mode
External Internal loopback mode
00-1C-C4-FB-DC-B2 Default MAC address (Hardware LAN address)
Multicast address list
Ethernet Communication medium
FF-FF-FF-FF-FF-FF MAC address (Current LAN address)
128 Minimum receive buffers
256 Maximum receive buffers
Yes Full duplex enable
Yes Full duplex operational
00-1C-C4-FB-DC-B2 MAC address (Current LAN address)
TwistedPair Line media type
100 Line speed (mbps)
Enabled Auto-negotiation
Enabled Flow control
Disabled Jumbo frames
0 Failover priority
Link Up Link state

Re: NIC MAC address change

Hoff — Tue, 15 Dec 2009 15:56:10 GMT

Go look at the Broadcom Corporation NetXtreme BCM5704 NIC to see if the chips are socketed; while I'd tend to guess not, but it can be worth a look.

Changing the address can be done via sys$qio. See the network driver information in this manual:

ftp://ftp.hp.com/pub/openvms/doc/AA-PV6SG-TK.PDF

Or Google for examples of using the NMA$C_PCLI_PHA itemcode.

Re: NIC MAC address change

dennis cooper — Tue, 15 Dec 2009 19:05:45 GMT

Can this be done at system level? LANCP? or OTHER?