Re: Comcast problems again

On Thu, May 26, 2011 at 9:57 PM, Carey Tyler Schug
<[email protected]> wrote:
> On 05/25/2011 11:58 PM, Trev Peterson wrote:
>>
>> sub-interfaces are not VLAN trunking.  You can configure sub-interfaces
>> on non-VLAN aware equipment it just means they share the same broadcast
>> domain.  On a single port router connected to a dumb hub (not switch) I
>> can configure 100+ subnets on the router connected to the switch.
>> Sub-interfaces are merely logical divisions of the physical port.
> OK,  sub-interfaces are returning from the depths of memory.  I took a
> CCNA class, the first CCNP class, and passed the CNA license in the 2004
> time frame, but never used the knowledge, so it has been slipping into
> forgotten nooks and crannies.  In class, I think we only used
> sub-interfaces between routers, maybe between switches.
>
> So I could connect my firewall to a dumb hub, and ports on it to a
> switch for each of my internal subnets?  Or a switch that supports
> sub-interfaces and VLANs, for which (maybe?) a Cisco 1900-EN would
> qualify.  Cool, that sounds workable.  if the 1900 won't work, I'll need
> to look for a small dumb hub, I think the only ones I have left are a 24
> port with a noisy fan and a 10Base2 hub., .  I wonder if I could find
> one of the very small number of 100BaseT hubs manufactured.
>
> And presumably I can configure sub-interfaces on the firewall
> computer....have to learn how to do that....
>
> --Carey
>> I hope this doesn't sound condescending.
> Not at all, I appreciate the corrections.
>>   You have a lot of equipment
>> but need to learn more of the fundamentals of routing/switching.
> mostly re-learn what I have forgotten with the passage of time.
>>> What I am still looking for on the web is an explanation of how traffic
>>> coming back to a system is routed to the correct location, and why
>>> masquerading is different so that Comcast can break it.   And if there
>>> is a "firewall" solution that Comcast can't detect or break.
>> Basic networking coursework (like I mentioned above) will teach you
>> about ports and how NAT works.
> If I could afford thousands of dollars for Cisco courses, I could just
> buy a commercial grade internet connection.  I need something on the web
> or a book I can get at a library.  I have a set of router 11.1 IOS
> books, if you think it would be int here, I can start searching, but it
> is a whole shelf of books.
>>   I've tried to explain that to Comcast
>> there is no difference between NAT and Masquerading but maybe wikipedia
>> can explain it better:
>>
>> http://en.wikipedia.org/wiki/Network_address_translation
> I read that before you sent it, and think I understood enough.  So we
> will assume the HOWTO in my previous post is wrong,.  Or maybe those
> instructions are for a different variation of Masquerading that would
> work, but I don't feel competent to install source patches on my Linux
> kernal...patches from 2005 that may no longer work without rewriting, of
> course.
>
> It still doesn't explain how the web side of NAT looks different
> compared to a single computer so Comcast can break it,

What was your test that showed Comcast was breaking it?

btw, I have been doing NAT with comcast for years.  3 boxes are active
right now, no problem.

>  and if there is
> some way to tweak NAT so Comcast won't break it.  Like force NAT to use
> a smaller range of translated port numbers?

What range does a single browser use?


-- 
Carl K
-- 
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