Why does my router have three MAC addresses? in Wireless Networking http://www.dslreports.com/forum/r20797106 en Tue, 02 Dec 2008 05:27:19 EDT Tue, 02 Dec 2008 05:27:19 EDT Re: Why does my router have three MAC addresses? http://www.dslreports.com/forum/remark,20829511 rsenthilkuma : Hi,
In WRT54G router have five ports. one for WAN(Internet) and remaining four ports are LAN.
1. LAN port have one MAC address(all ports are bind this Single MAC).(Local Network: 00:14:BF:D6:CD:28)

2. Then WAN Port have one MAC address, and one more MAC address (Router: 00:14:BF:D6:CD:29)

3.Wireless 54G port MAC address. so ur product have 3 MAC address.Wireless:(00:14:BF:D6:CD:2A)

the first 6 digits are vendor code (00:14:BF - Cisco-Linksys )& next 4 digits are product code (D6:CD - WRT54G).
then the remaining two digits are port numbers. so ur three MAC address first 10 digits are same.

in any clarification reply me :)]]> http://www.dslreports.com/forum/remark,20829511 Tue, 22 Jul 2008 05:58:26 EDT Re: Why does my router have three MAC addresses? http://www.dslreports.com/forum/remark,20802868 stevech0 : the idea in networking is that the manufacturer assigns a unique MAC address to every network interface that he manufacturers. There are manufacturer ID blocks of MAC addresses that are coordinated/registered via an authority.]]> http://www.dslreports.com/forum/remark,20802868 Wed, 16 Jul 2008 21:02:54 EDT Re: Why does my router have three MAC addresses? http://www.dslreports.com/forum/remark,20801019 CJS : Thanks for the informative replies, everyone. I guess it makes sense that each network interface would have its own MAC address for special cases where they could conflict when used simultaneously. :)]]> http://www.dslreports.com/forum/remark,20801019 Wed, 16 Jul 2008 15:07:24 EDT Re: Why does my router have three MAC addresses? http://www.dslreports.com/forum/remark,20797233 Bill_MI : Design and convention. Three interfaces, three MACs. By design, no two interfaces in the WORLD should have the same MAC. Of course, that doesn't mean it's not bent here and there (MAC cloning for example).

I had an interesting happening with MACs in OpenWrt. Seems they didn't fix up WAN/LAN as separate MACs after default settings. Since you can bridge LAN/WAN in a PPPoE/tunneling-type system - don't try it when the MACs are the same. :-)]]> http://www.dslreports.com/forum/remark,20797233 Tue, 15 Jul 2008 21:32:33 EDT Re: Why does my router have three MAC addresses? http://www.dslreports.com/forum/remark,20797213 jimbopalmer : How confused is a laptop with both wired and wireless access going to be if those MAC Addresses are the same? What if this router is "inside" another home network the laptop is connected to (one network wireless and another network wired)

MAC Addresses are almost free, use all you want, they will make more.
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I tried to remain child-like, all I achieved was childish.]]> http://www.dslreports.com/forum/remark,20797213 Tue, 15 Jul 2008 21:27:40 EDT Re: Why does my router have three MAC addresses? http://www.dslreports.com/forum/remark,20797196 PetePuma : You need a MAC address per physical interface, not just one for the whole router. You essentially have 3 different segments (WAN, wired LAN, wireless LAN).]]> http://www.dslreports.com/forum/remark,20797196 Tue, 15 Jul 2008 21:25:40 EDT Why does my router have three MAC addresses? http://www.dslreports.com/forum/remark,20797106 CJS : I have the ubiquitous Linksys WRT54G router, and when I go into its configuration settings under "Status", I can choose either "Router", "Local Network", or "Wireless." All of those sections list a MAC address that is slightly different--only the last hex digit varies:
quote:
Router: 00:14:BF:D6:CD:29
Local Network: 00:14:BF:D6:CD:28
Wireless: 00:14:BF:D6:CD:2A


So since my router is hooked up to my DSL modem, my DSL modem sees the "Router" MAC address, but any computer that uses the router on the LAN will see the LAN or wireless MAC address, depending on whether they are connected via ethernet or wireless.

So the question is, why are there three MAC addresses for the same router? I thought the whole point of the MAC address was to uniquely identify the router, and I don't see how there would be any networking conflicts if one MAC address was used in all the above three cases. So why not just use one MAC address?

Thanks for any insight/help. :)]]> http://www.dslreports.com/forum/remark,20797106 Tue, 15 Jul 2008 21:09:31 EDT