[wplug] Suggestion for discussion

[Terence J. Golightly]

Brian,


On 07/05/2010 07:23 PM, Brian A. Seklecki wrote:
> On Mon, 2010-07-05 at 14:18 -0400, Terence J. Golightly wrote:
>> subnet mask to find where network a packet should be routed/nat'd to.
>
> Hopefully they've explained Class-less v.s. Class-ful networks?

It was touched upon in a note, but not gone into in detail.  This course 
is just basically a beginners certification. The next section(s) (MNP) 
probably get much deeper into this subject matter. The last section, 
will be CCNA course for certs.
>
> The big question is this:
>
>   - Does the local host, when forwarding a packet to a non-local host,
>     need to forward the packet to its default gateway (or other
>     gateway per the routing table / static routes), or does the
>     packet stay within the local LAN (via the directly connected
>     interface)
>
>      - Of course, if the destination is on the local subnet, you just
>        need to ARP (or whatever L2 protocol discovery for your media),
>        and transmit to that MAC/L2 addr.  No router needed.
>
>      - If the destination isn't local:
>
>       -- Back in classful networks, it was easy to figure out based on
>          the class of the subnet (1st octet).
>       -- Now that classes are gone, you need to compare your
>          interface subnet mask, regardless of the class
>          designation in the 1st octet.
>
>
> e.g., in 1995, if I was addressed 10.1.2.3, and I wanted to send to
> 10.4.5.6, i would know that 10.4.5.6 is local, so just ARP and send.
>
> In 2010, if I'm 10.1.1.3 with a subnet mask 255.255.255.248, and I want
> to send to 10.1.1.10, I would know to transmit the L3 packet inside a L2
> packet with the MAC address of my default gateway (probably 10.1.1.1),
> which will forwarded it on appropriately.
>
> http://digitalfreaks.org/~lavalamp/CIDR.html
>
> I can give you all the CCNA-level training you need.

Thanks for the link and offer.  I already notice quite a bit of 
vernacular that I'll need to learn.  All in good time though.  I am 
testing Thursday for certification.

>
> ~BAS (PS, Evo>  *)

Terry