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Thread ID: 65165	2006-01-10 01:29:00	Just wondering...	Deve99 (9575)	Press F1

Post ID	Timestamp	Content	User
419514	2006-01-10 01:29:00	What is a subnet? how it it used?	Deve99 (9575)
419515	2006-01-10 01:32:00	If u mean, as in a network read this (en.wikipedia.org)	Speedy Gonzales (78)
419516	2006-01-10 02:38:00	Subnet's are as simple or complex as you want to make it. Instead of giving a super long technical explanation, just try this: 192.168.236.x subnet 255.255.255.0 "x" is a unique number for each of your network devices, such as PC's, printers and firewalls. In a small network, a popular set up is using a hardware based ADSL modem/firewall to share a broadband connection. On the outward facing connection, use the internet provider's supplied IP information, usually a single address. On the inward facing connection, use one of the 192.168.236.x addresses. It's important to note it, since this will become your "default gateway" when you set up other PC's. If you care, many other people will be also using the same 192.168.236.x address, but it won't affect you in any way. For small networks it usually easiest to "hard-code" the IP number, by manually assigning each device a unique number. If you're feeling adventurous, DHCP will automatically lease out IP addresses. For wireless, the same rules apply. (Note to techies: I know there are many other IP subnet possibilities, and that 192.168.x.x are reserved addresses)	kingdragonfly (309)
419517	2006-01-10 03:05:00	But a subnet mask of 255 . 255 . 255 . 0 does not illustrate a subnet . That specifies the whole class C range 192 . 168 . 236 . xxx . The host part is the xxx part of the address . That is a decimal representation of the 8 bits, alowing 256 (-2) hosts in the Class C net . That 256 address range in the network could be split into 16 subnets, using the mask 255 . 255 . 255 . 240, for example . Then the first (most significant) four bits of the host part are used as a subnet address . Thus there are four bits left for the host address, allowing 14 hosts in each subnet . (In each subnet, the "all ones" and "all zero" host parts are reserved for broadcasts) The last eight bits are represented as one number again, so addresses might look as if they belong to (in the example) 192 . 168 . 236 . 0 net, but 192 . 168 . 236 . 20, 192 . 168 . 236 . 36, 192 . 168 . 236 . 68, and 192 . 168 . 236 . 132 is each in a separate subnet . . . so they can't "see" each other unless there is a router there . Each of those numbers belongs to host "4" in one of the 16 subnets specifies by that "240" last part opf the subnet mask . It's all a bit confusing . Normally it's something you don't need (or want) to know . :D	Graham L (2)
419518	2006-01-10 03:40:00	I'm guessing most home users don't further divide a subnet. As you've stated, subnets only works in there's some form of router(s) seperating 'em. How many people actually run multiple routers / firewalls at home? ;)	kingdragonfly (309)
419519	2006-01-10 03:54:00	The IP address system was designed a long time ago . The Internet started with two hosts . Then there were 3, four, five . . . The need for subnetting arose when the Internet exploded, and suddenly there was a shortage of IP addresses . The three classes were too widely different in size . . . a class A allowed 2^24 hosts (-2 ;)) . (There's a whole class A range allocated to the test address 127 . 0 . 0 . 1 . ;) ) Not many businesses or organisations had that many hosts, yet some of those who got in early had whole Class A ranges assigned to them . Class Bs, with 2^16 (-2) were a bit more reasonable . . . only 65000 hosts, then class Cs had 254 . But even class Cs were wasteful units of allocation in a lot of cases . So subnets were invented . When I was playing with routers at home, I just gave each network a class B . :cool: My big internet wasn't connected to anything else, so I could do that . The shortage of IP addresses is why ISPs don't give permanent IP addresses to everyone . Dynamically assigned addresses mean that they can be used by people who are on line . If they are not, the Ip address can be used by someone else .	Graham L (2)
419520	2006-01-11 02:50:00	Hey, you're preaching to the converted. I was in San Francisco, near the Netscape office. They kindly donated the commerce server to the non-profit where I worked, and I created one of the first 500 web-sites that securely accepted credit cards. All my work mates said "buy Netscape stock; there about to make their IPO." Unfortunately after expenses, I had about $40 a month left over. Man, environmental groups paid bad! I'm also certified by Microsoft in TCP/IP, when Microsoft was still giving out this certification. (It's now inclusive to several exams, but not exclusive to one.) Subnetting is a complex subject, and typically not that relevant to home users, once they got their network set up. If you're a Cisco engineer on the other hand, but that's why they get paid the big backs :)	kingdragonfly (309)
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