Text 6131, 237 rader
Skriven 2005-03-26 16:47:30 av mark lewis (1:3634/12)
Kommentar till text 5909 av CHARLES ANGELICH (1:123/140)
Ärende: lan
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ML>> true... one should start from ground zero...
CA> Based on the comments by Alan Z. it seems that some utility to
CA> ID the NIC and a check at the manufacturer's website for newer
CA> drivers would be a good idea _before_ trying to setup
CA> networking. :-)
in some cases, yes, that can help...
[trim]
CA> For me information in a forum is not really worth much. I only
CA> search through a forum if Google offers no other sources of
CA> that same information.
taken under consideration...
CA>>> A set of webpages including screenshots of menus would be
CA>>> best IMO. A 'before' set of menus as found in a fresh
CA>>> install and then 'after' as they should look when
CA>>> configured would be nice.
ML>> hummm...
CA> I know, sounds like too much trouble but they can be low
CA> quality JPGs and "a picture is worth a thousand words" ya'
CA> know?
yeah... but i can't even begin to count the times that my screen looked nothing
like the one in the tutorial or even in some of the books ;)
[trim]
ML>> yeah, that can be a problem... on the netmask stuff, that's
ML>> TCP/IP related and would be located in areas that
ML>> specialize in teaching about TCP/IP basics...
CA> Maybe so but do people really want to _study_ TCP/IP or do
CA> they just want a direct/simple answer?
i dunno that there is a simple answer...
a netmask is, as it says, a mask... actually, you and i can consider it an AND
mask... ya gotta go to the BIT level, too... the easy thing to remember is that
255.255.255.0 lets everything in where the first three octets are the same...
ie: 192.168.5.x with 255.255.255.0 allows 192.168.5.*
192.168.45.x with 255.255.255.0 allows 192.168.45.*
but neither will allow the other without some assistance
here's another
ie: 192.168.5.x with 255.255.0.0 allows 192.168.*.*
192.168.45.x with 255.255.0.0 allows 192.168.*.*
so both networks can talk to each other...
one problem, too, is that some rules are enforced by some setups... since
192.168.x.y is classified as a Class C network, many times, only 255.255.255.0
is allowed...
ok, here's the bit level stuff... let's take a connection between 192.168.5.5
and 192.168.5.10...
192.168.5.5 == 11000000 10101000 00000101 00000101
192.168.5.10 == 11000000 10101000 00000101 00001010
255.255.255.0 11111111 11111111 11111111 00000000
the netmask gives us 11000000 10101000 00000101 00000000
the first three octets in the masked ANDed address match with the first three
octets of each of the addresses... the last octet we don't care what address it
is... so the data flows...
in the above, there are 24 "mask" bits and 8 "host" bits...
nnnnnnnn.nnnnnnnn.nnnnnnnn.hhhhhhhh
the "fun" part comes when you want to subnet a network... lets play with taking
the 192.168.4 network (256 addresses) and split it down into various subnets...
a netmask of 255.255.255.128 gives us two subnets with 126 addresses each...
the first and last address in each block is reserved (256 / 2 = 128 - 2 = 126
usable) ... the first is the network's address and the last is the broadcast
address... this gives us 25 "mask" bits and 7 "host" bits...
'n' = "mask" bits 'h' = "host" bits
2 subnets nnnnnnnn.nnnnnnnn.nnnnnnnn.nhhhhhhh 126 addresses
255 255 255 128
4 subnets nnnnnnnn.nnnnnnnn.nnnnnnnn.nnhhhhhh 62 addresses
255 255 255 192
8 subnets nnnnnnnn.nnnnnnnn.nnnnnnnn.nnnhhhhh 30 addresses
255 255 255 224
16 subnets nnnnnnnn.nnnnnnnn.nnnnnnnn.nnnnhhhh 14 addresses
255 255 255 240
32 subnets nnnnnnnn.nnnnnnnn.nnnnnnnn.nnnnnhhh 6 addresses
255 255 255 248
64 subnets nnnnnnnn.nnnnnnnn.nnnnnnnn.nnnnnnhh 2 addresses
255 255 255 252
so... taking our example from up above...
192.168.5.5 == 11000000 10101000 00000101 00000101
192.168.5.10 == 11000000 10101000 00000101 00001010
255.255.255.240 11111111 11111111 11111111 11110000
the netmask gives us 11000000 10101000 00000101 00000000
so these two can talk directly... however, using a 6 address subnet...
192.168.5.5 == 11000000 10101000 00000101 00000101
192.168.5.10 == 11000000 10101000 00000101 00001010
255.255.255.248 11111111 11111111 11111111 11111000
the netmask gives us 11000000 10101000 00000101 00001000
and they can't talk because the .5 address doesn't fit into the ANDed mask with
the .10 (ie: in the same network)... here's the break down...
Subnet Netmask Host Range Broadcast
192.168.4.0 255.255.255.248 192.168.4.1 - 6 192.168.4.7
192.168.4.8 255.255.255.248 192.168.4.9 - 14 192.168.4.15
192.168.4.16 255.255.255.248 192.168.4.17 - 22 192.168.4.23
192.168.4.24 255.255.255.248 192.168.4.25 - 30 192.168.4.31
192.168.4.32 255.255.255.248 192.168.4.33 - 38 192.168.4.39
192.168.4.40 255.255.255.248 192.168.4.41 - 46 192.168.4.47
192.168.4.48 255.255.255.248 192.168.4.49 - 54 192.168.4.55
192.168.4.56 255.255.255.248 192.168.4.57 - 62 192.168.4.63
192.168.4.64 255.255.255.248 192.168.4.65 - 70 192.168.4.71
192.168.4.72 255.255.255.248 192.168.4.73 - 78 192.168.4.79
192.168.4.80 255.255.255.248 192.168.4.81 - 86 192.168.4.87
192.168.4.88 255.255.255.248 192.168.4.89 - 94 192.168.4.95
192.168.4.96 255.255.255.248 192.168.4.97 - 102 192.168.4.103
192.168.4.104 255.255.255.248 192.168.4.105 - 110 192.168.4.111
192.168.4.112 255.255.255.248 192.168.4.113 - 118 192.168.4.119
192.168.4.120 255.255.255.248 192.168.4.121 - 126 192.168.4.127
192.168.4.128 255.255.255.248 192.168.4.129 - 134 192.168.4.135
192.168.4.136 255.255.255.248 192.168.4.137 - 142 192.168.4.143
192.168.4.144 255.255.255.248 192.168.4.145 - 150 192.168.4.151
192.168.4.152 255.255.255.248 192.168.4.153 - 158 192.168.4.159
192.168.4.160 255.255.255.248 192.168.4.161 - 166 192.168.4.167
192.168.4.168 255.255.255.248 192.168.4.169 - 174 192.168.4.175
192.168.4.176 255.255.255.248 192.168.4.177 - 182 192.168.4.183
192.168.4.184 255.255.255.248 192.168.4.185 - 190 192.168.4.191
192.168.4.192 255.255.255.248 192.168.4.193 - 198 192.168.4.199
192.168.4.200 255.255.255.248 192.168.4.201 - 206 192.168.4.207
192.168.4.208 255.255.255.248 192.168.4.209 - 214 192.168.4.215
192.168.4.216 255.255.255.248 192.168.4.217 - 222 192.168.4.223
192.168.4.224 255.255.255.248 192.168.4.225 - 230 192.168.4.231
192.168.4.232 255.255.255.248 192.168.4.233 - 238 192.168.4.239
192.168.4.240 255.255.255.248 192.168.4.241 - 246 192.168.4.247
192.168.4.248 255.255.255.248 192.168.4.249 - 254 192.168.4.255
you can see that the .5 address is in the first network whereas the .10 is in
the second network... they can't talk to each other directly thru a hub or
switch so they need a router between them...
this is all the "easy" stuff... "easy" because its only working with the last
octect... but it is basically the same thing up thru the other octects... from
what i've seen, if one wants to really learn all about netmasks and subnets and
such, one is better off to take a networking class like a cisco certification
class or similar... its either that or, like me, you keep plugging away at it
until it really starts to fit and make sense ;)
ML>> netbeui is used because that's what m$ designed their
ML>> networking (network neighborhood) stuffs around... the big
ML>> question is whether or not to use netbeui wrapped within
ML>> tcp/ip packets... netbeui is not routable and thus cannot
ML>> travel between different wiring networks... it needs a
ML>> routable protocol like tcp/ip to carry it into different
ML>> wiring networks...
CA> Define "wiring networks" please.
my phrasing... used to signify a network of machines physically connected by
wires to one hub or stack of chained hubs... think of an office building where
each floor may be its own network block...
1st == 192.168.1.1 - 255
2nd == 192.168.2.1 - 255
3rd == 192.168.3.1 - 255
4th == 192.168.4.1 - 255
etc...
all the machines on each floor can talk to each other (with a netmask of
255.255.255.0) but can't talk to other machines on other floor... there would
have to be a router connection connecting the floors together for them to be
able to communicate across the network boundaries...
ML>> i know that last part sounds confusing and that's where the
ML>> use of a hub or switch comes in to play verses using a
ML>> router... in most cases...
CA> Sounds like NetBEUI is a leftover from the "network wars" when
CA> IBM was pushing token ring and others Novell or Lantastic. :-)
lantastic was a netbios network as was personal netware ;) there were others,
too, but i can't think of them at the moment...
ML>> m$ has also gone so far, in recent releases, as to not use
ML>> netbeui stuffs... they are still using that method but now
ML>> they are building the netbeui packets directly without
ML>> using the netbeui protocol to do it for them... they are
ML>> then taking these self-built packets and transporting them
ML>> via tcp/ip... the overall effect is the same but the under
ML>> the hood methods are much different...
CA> Sounds as though they are 'hiding' NetBEUI to me which doesn't
CA> surprise me in the least. This nonstandard methodology being
CA> forced onto users has gone _way_ past the point of being
CA> competitive into the realm of egos and arrogance IMO.
i can agree to a point... i can't say that they are "hiding" netbeui but i
think they see the greater benefits of using tcp/ip since it is routable... i
think part of the problem is that they still need some way to keep their stuff
encapsulated to make it somewhat harder to snoop on... then again, it may be as
simple as not wanting to rewrite all the guts of the networking stuff that's
built around netbios when they only need to remove one network layer and fake
that layer in one driver...
it may also be part of their propietary stuffness trying to keep things not
working with other OS' so that folk will stay in the m$ henhouse...
i wonder what'll happen to m$ when billyboy passes on...
)\/(ark
* Origin: (1:3634/12)
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