topic Re: How to set an Inverted MAC in Firewall and Security Management

How to set an Inverted MAC

Julie_Paul — Wed, 15 Aug 2018 14:56:33 GMT

Can we manually configure what the inverted MAC Address will be in R80.10. Has anyone done this or seen it work for R80.10? Do you have the procedure?

it is the “inverted back source MAC Address” that appears in the switch ARP table

If one was to run a ‘fw ctl zdebug –m cluster + select’ you would see in the logs something like this:

;[cpu_7];[fw4_0];fwha_select_ip_packet: The inverted back source MAC address will be 00:16:63:BF:23:FF;

When one does a lookup of the vendor for MAC Address 00:16:63 is states the vendor of KBT Mobile. Would like to know if there is a way to configure it to use some a different MAC, like 00:1C:7F or 00:90:FB or possibly an older Noxia MAC

This is what the ARP table looked like:

* - primary entry, G - Gateway MAC, (R) - Routed MAC, O - Overlay MAC

age - seconds since last seen,+ - primary entry using vPC Peer-Link

VLAN MAC Address Type age Secure NTFY Ports/SWID.SSID.LID

---------+-----------------+--------+---------+------+----+------------------

* 13 0000.0000.0200 dynamic 0 F F Eth102/1/31

* 13 0016.63bf.23ff dynamic 0 F F Eth102/1/31

* 13 001c.7f62.ed66 dynamic 0 F F Eth102/1/31

Re: How to set an Inverted MAC

PhoneBoy — Thu, 16 Aug 2018 03:52:19 GMT

Probably a better question for Appliances and Gaia‌.

Hopefully one of Alexander Kim‌'s team can provide some commentary.

Re: How to set an Inverted MAC

_Val_ — Thu, 16 Aug 2018 07:42:04 GMT

In your list, the first MAC belongs to ClusterXL: 0000.0000.0200. This is the source MAC address for CCP frames.

I am not sure about the second one. Did you enable vMAC by any chance?

Re: How to set an Inverted MAC

_Val_ — Thu, 16 Aug 2018 07:45:04 GMT

Answering my own question. No, neither one looks like vMAC. You can find some details here: How to enable ClusterXL Virtual MAC (VMAC) mode

The only logical conclusion is that you do have some third party sending frames to the same switch port.

Re: How to set an Inverted MAC

PhoneBoy — Thu, 16 Aug 2018 14:14:01 GMT

There's no specific way to control what the inverted MAC will be, but it is based on your original MAC as well as the kernel parameters fwha_mac_magic and the fwha_mac_forward_magic.

Re: How to set an Inverted MAC

Julie_Paul — Wed, 22 Aug 2018 17:04:26 GMT

Thanks for the response!