Re: ARP requests on my net?

Edward Krack wrote:
Edward Krack:


It has to know where to go. Can you drive cross country
without a road map?


Users computer types in a URL to browse the net.
Users computer is config to use DNS server to resolve the
the name in the URL to an IP address.
TCP/IP uses ARP.

Eh? Why does it need the MAC? And why does it need the MAC
of my router? My router is the one which needs to know
MACs. AFAIK, TCP/IP uses IP, not ARP. I just went and got
my handy-dandy "Understanding TCP/IP (tm)" manual and looked
in the index, and ARP isn't even mentioned. That's Transmission
Control Protocol over Internet Protocol. The layers are,
AIUI,

HTTP, SMTP, FTP, etc.
TCP
IP (ICMP)
LAN/PPP/Frame Relay/ATM or etc.
physical

ARP should be in Level 2, the P2P LAN layer (Ethernet).
Nothing to do with IP. IP can run over SLIP, PPP, Frame
Relay, ATM. It shouldn't care about stuff needed by
the layer 2 protocol for physical routing. Anyway, TCP is
layer 4, two levels above MACs.

Host found. Session established.
Users Computer: Hello, are you there?

Everything up to here needs only IP addresses, I thought.
The router needs to know the MACs associated with the
IP addresses so it can forward the messages, but ARP
is finding layer 2 protocol, not layer 3 like IP.
AIUI, ARP is used for the P2P stuff at layer 2.
Why does my Linux machine need to know the MAC for the
router?

DNS: Yes I'm here. Okay, lets ride.
ARP: Rand McNally truckers road map.

But the ARP is being done on the router. And even if it
weren't, why would my computer want to know the MAC
of a computer it has no direct connect to?

WWW: Malicious or Invalid?


Unless dslmodem uses DCHP and was infected from previous
owner.

Eh? On the LAN side, I use fixed IP, for the computers,
and for the router. The router on the WAN side accepts DHCP,
but my computer never sees that address. The modem, facing
back to the router and computer, has a fixed IP on 168.x.x.x.

Mike
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