Re: [gentoo-user] Linksys router BEFSR41 loosing internet

[Dale]

Peter Humphrey wrote:
> On Monday 20 December 2010 09:37:48 Dale wrote:
>
>
>> I set it up like this.  The modem uses DHCP to get the IP from AT&T.
>> My local IP from the modem is 192.168.1.2.  Then the router has the
>> IP 192.168.2.1 for my connection to the puter.  The IP of my puter
>> is 192.168.2.5.  The next puter will be 192.168.2.6 or something
>> different anyway.
>>
> The one thing you didn't mention there is the outer address of your
> router. It needs to be 192.168.1.x where x is anything other than 2. It
> needs to be on the same network segment as the inner side of your modem.
>
>

Yep, front end is 192.168.1.4 or 5 I think.  Something close to that.   
The last number may be different.  It may be .2 or something.

>> I need to read up on the netmask thing some more.  It's still murky
>> for sure.
>>
> (What follows has grown rather long. I hope it doesn't come over too
> much as a lecture.)
>
> It's fairly straightforward once you get the hang of it. The address of
> a device is a 64-bit number, expressed as four 16-bit numbers joined
> with dots. It's just easier to read when split into chunks, but it is
> really a 64-bit number. As in decimal arithmetic, the right-hand digit
> is the least significant.
>
> An interface address consists of two parts: the leftmost part defines a
> group of addresses (the network part) and the rightmost part specifies
> the number of the interface in that group (the host part). The function
> of the network mask is to specify where the boundary is between the
> network part and the host part.
>
> Two conventions are used for expressing where that boundary is: the
> older method is to write, say, 255.255.255.0, which indicates that the
> first 24 bits (three eight-bit numbers - 255 is all-ones in eight bits)
> belong to the network and anything to the right of those can be
> allocated to interfaces in that network. That convention dates from the
> era of plenty of IP addresses in the world and goes along with Class A,
> B, C or D. A class A network has a mask of 255.0.0.0, class B has
> 255.255.0.0, class C has 255.255.255.0 and a class D (never used in the
> wild as far as I know) would have 255.255.255.255.
>
> Since the meteoric growth of the Internet this class scheme has become a
> handicap, and a finer division of network scope has become necessary, to
> allow use of, say, 255.255.255.248 as a net mask. Rather than specifying
> a plethora of new classes (we'd need anything up to 60), a shorthand
> notation has been invented in which we just append a number to an
> address to specify the number of bits that identify the network, with
> the rest identifying the host on it (strictly speaking, a host's
> interface on the network, as a host may have more than one interface -
> sometimes even on the same network). This scheme is known as CIDR
> notation. Thus your modem's inner address is, I assume, 192.168.1.2/24,
> which is the same as writing 192.168.1.2 with a mask of 255.255.255.0.
>
> That mask 255.255.255.248 I mentioned specifies 29 bits for the network
> address and three for the hosts on it; that's enough for six computers
> once the ..0 and ..7 addresses are reserved for network address and
> broadcast address. A lot of ISPs use such a scheme for allocating
> address ranges to their customers.
>
>
>> How's it look?  Think it will work for a while?
>>
> Once you've set your router's outer address correctly, yes.
>
> Sorry I was asleep overnight and had to leave you to the tender mercies
> of your compatriots.   :-)
>
> Again, apologies if I've seemed to want to teach my grandmother to suck
> eggs.
>
>

Taking a nap is fine.  I do that sometimes myself.  If worse came to 
worse, I could set my puter to DHCP and hooked straight to the modem.  
That always works.

I seem to have the stuff set up correctly now.  I may try to hook up the 
second rig at least for testing anyway.  I should have set the IP and 
set it to start ssh before the last shutdown.  I didn't tho.  Oh well.

I'm starting to grasp the netmask thingy.  It just has to soak in a 
little bit.  lol

Thanks for the help.

Dale

:-)  :-)