DSL mac address?

[Mirko]

Hello all,

the home access point connected to the phone line have a mac
address or no ?
I think it has one MAC ,but I'm not sure.
PPPoE used in DSL modem/router encapsulates IP packets inside
ethernet frame ?

Thanks

[Grant Taylor]

Post by Mirko
Hello all,

Hi,

Post by Mirko
the home access point connected to the phone line have a mac address
or no ?

I assume that you're asking about the /outside/ network interface.

It depends on the specific technology in use.

Post by Mirko
I think it has one MAC ,but I'm not sure.

There are almost always (at least) two interfaces network interfaces;
one /outside/ and one /inside/. They usually are Ethernet like and have
a MAC address.

That's traditional routers.

Wireless routers usually have an additional /inside/ interface that is
the wireless portion.

Wireless access points are in and of themselves different critters.
They typically have a wired interface and a wireless interface (bridged
together), each of which have their own MAC.

Note: Wired and wireless MACs are different from each other.
(Simplistically, Wireless MACs are a superset of wired MACs.)

Post by Mirko
PPPoE used in DSL modem/router
encapsulates IP packets inside
ethernet frame ?

Yes.

The "E" is the pertinent part. There is also PPP over ATM, which being
ATM does not use MAC addresses. Hence depending on the specific technology.

Post by Mirko
Thanks

You're welcome.

[Mirko]

Post by Grant Taylor

Post by Mirko
Hello all,

Hi,

Post by Mirko
the home access point connected to the phone line have a mac address
or no ?

I assume that you're asking about the /outside/ network interface.
It depends on the specific technology in use.

Post by Mirko
I think it has one MAC ,but I'm not sure.

There are almost always (at least) two interfaces network interfaces;
one /outside/ and one /inside/. They usually are Ethernet like and have
a MAC address.
That's traditional routers.

They have the internal/ private lan interfaces with private IP ,
and one public throught PPPoE .

Post by Grant Taylor
Wireless routers usually have an additional /inside/ interface that is
the wireless portion.
Wireless access points are in and of themselves different critters.
They typically have a wired interface and a wireless interface (bridged
together), each of which have their own MAC.
Note: Wired and wireless MACs are different from each other.
(Simplistically, Wireless MACs are a superset of wired MACs.)

I know, using a packet sniffer as wireshark or airodump it's
visible the MAC address of a AP router.
It's different from ethernet interface ( they have typically 4
ethernet port with the same MAC).

Post by Grant Taylor

Post by Mirko
PPPoE used in DSL modem/router
encapsulates IP packets inside
ethernet frame ?

Yes.
The "E" is the pertinent part. There is also PPP over ATM, which being
ATM does not use MAC addresses. Hence depending on the specific technology.

How may I know the MAC address inside PPPoE frames? AP/routers
don't indicate MAC address of the public interface.
They have same version of linux/BSD embedded, a small web server,
and a little shell like busybox accesible via telnet.

Thanks

Post by Grant Taylor

Post by Mirko
Thanks

You're welcome.
--

[Grant Taylor]

Post by Mirko
They have the internal/ private lan interfaces with private IP ,
and one public throught PPPoE .

That is very common.

It is possible to have public / globally routed IPs on the LAN.

Post by Mirko
I know, using a packet sniffer as wireshark or airodump it's visible
the MAC address of a AP router.

Yep.

Post by Mirko
It's different from ethernet interface ( they have typically 4 ethernet
port with the same MAC).

I'm not sure what you're referring to here.

I can't tell if it's the fact that wireless frames have 3 or sometimes 4
MAC addresses, or something about seeing the same mac from multiple
ports on a switch (or hub).

Post by Mirko
How may I know the MAC address inside PPPoE frames? AP/routers don't
indicate MAC address of the public interface.

It is highly dependent on the router. Some may expose it somewhere in
the management interface. Some may require running a command on the router.

You may be able to get your ISP to provide it.

Depending on the router, you may be able to hook a sniffer up to the
outside / public interface of the router.

Post by Mirko
They have same version of linux/BSD embedded, a small web server,
and a little shell like busybox accesible via telnet.

I don't think I've heard of any SOHO routers that have any BSD varient.
I've heard of plenty distros that you can install on an old computer
that run one BSD or another.

Linux and VXWorks seem to be quite common.

Post by Mirko
Thanks

You're welcome.