Can't connect thru a router

[Scott C. Best]

Scott:

 	Heya. I'd be very surprised if it was a MAC-related issue.
Firstly, she's VPN'd with work, so her ethernet-frames emerge on
her work LAN intact -- no intervening router touches them, or could
touch them. That's the underlying approach of VPN'ing, after all:
it captures the raw ethernet frames in "virtual interfaces" and
delivers them to a remote network. Secondly, even if she wasn't
VPN'd, the "source MAC-address" of the ethernet frame as seen by
her work PC will be from the last router (or switch) in the chain
of routers that the packets used on their way. Unlike VPN traffic,
there is no provision in normal TCP/IP traffic to "preserve" the
MAC-address of the original source.

 	The MAC-address cloning you describe is very useful, though,
when your own broadband modem has "memorized" the PC it was originally
connected to. ISP's used to do this as they didn't want broadband
customers to run multiple PC's on the their home LAN -- they wanted
1 PC per IP address. That wasn't very popular with their customers
(having more multiple PC's share an Internet connection was the
whole reason they *became* customers), and it was nearly impossible
to enforce -- they tried MAC-address memorization, and (in typical
Internet style) the router vendors countered with MAC-address cloning.
Some of them (including LinkSys), actually ask permission to clone
the MAC address when you run their optional installation software.

 	So if when Anita added her broadband router, she was unable
to access the Internet *at all*, then I would suspect the MAC address
was the issue. Otherwise, the signs point to an MTU-size problem.

cheers,
Scott

> It's very possible that the "doorway" to your office PC is programmed to
> only allow access from a particular MAC address. The MAC address of the
> router is different, so it will be rejected.
> If this is the case, you need to get the new address to your office IT
> dude, or in many cases, the router will have a "Clone MAC Address"
> feature, so you can set it to broadcast the same MAC as your home PC.
>
> Anita Mahoney wrote:
>
>>  Thanks for the response!
>>
>>  I am connected to the internet through a cable modem. I accessed my office
>> pc by using the VNC Viewer (I kept the VNC server active on my office pc)
<snip>