I have a lan device with the IP connected to a Linksys E2000 router running DD-WRT with the IP This router is configured as following, WAN Connection Type: Automatic DHCP.

This router then is connected to another router provided by my ISP, the IP is This last router is connected to a Optical Network Terminal.

My question is, when I arp in, only replies. Because all devices connected to it are in it's broadcast domain, so it's normal it can't see right?

Also does the MAC address of is seen in Or for exemple if I visit Google.com, does Google servers see this device MAC? Is the MAC carried all along the circuit inside the frame?

Thanks, I hope my question isn't too confusing.

  • Don't use the same network for both sides of a NAT...
    – cpt_fink
    Commented Apr 22, 2015 at 3:57

1 Answer 1


The MAC address is seen only by the two segments connected to each other. So, Google would not be able to see you MAC address. Furthermore, it is appropriate that your firewall would ARP with it's MAC address for the .254 address, because all devices need to first go through the firewall before they can reach the ISP gateway. If saw the real ARP address for, then you would wind up with either a loop, the firewall dropping that traffic or your firewall being rendered useless.

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