on linux, when using bonding,system.hw.macaddr doesn't shows real interface macs, only bond/vlan(/active?) interface

I need to use it for inventory so I had expect it to show all interfaces mac address not only bonding/active interfaces.

================= zabbix output:

1. zabbix_agent -p | grep system.hw.macaddr
   system.hw.macaddr [s|[bond0] xx:xx:xx:xx:xx:xx, [bond0.31] xx:xx:xx:xx:xx:xx]

================= interfaces:

bond0 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx
inet addr:xx.xx.xx.xx Bcast:xx.xx.xx.xx Mask:xx.xx.xx.xx
UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1
RX packets:30706617100 errors:0 dropped:269 overruns:0 frame:0
TX packets:28515758518 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:4869114470375 (4.4 TiB) TX bytes:6149591825243 (5.5 TiB)

bond0.31 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx
inet addr:xx.xx.xx.xx Bcast:xx.xx.xx.xx Mask:255.255.0.0
UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1
RX packets:2351078070 errors:0 dropped:0 overruns:0 frame:0
TX packets:2919817379 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:281189067609 (261.8 GiB) TX bytes:1834825494031 (1.6 TiB)

em1 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx
UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
RX packets:30702814778 errors:0 dropped:269 overruns:0 frame:0
TX packets:28515758518 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4868858156167 (4.4 TiB) TX bytes:6149591825243 (5.5 TiB)
Interrupt:36 Memory:d6000000-d6012800

em2 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx
UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
RX packets:3802322 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:256314208 (244.4 MiB) TX bytes:0 (0.0 b)
Interrupt:48 Memory:d8000000-d8012800

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:276923216 errors:0 dropped:0 overruns:0 frame:0
TX packets:276923216 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:27236503474 (25.3 GiB) TX bytes:27236503474 (25.3 GiB)