ICANN = Internet Corporation for Assigned Names and Numbers
IANA = Internet Assigned Number Authority
NIC = Network Information Center (not to be confused with network interface card acronym)
RIR = Regional Internet Registry
ICANN is responsible for
(1) governing domain names, IP/AS addr, protocol port numbers
(2) DNS root name servers (A to M)
==> part of (1) work is delegated to its subsidiary IANA as below
IANA governs all the ip addr assignment (asn/ipv4/ipv6) and delegates the allocation/assignment work to NIC(aka RIR) which exists in each region as below.
(as of Nov. 2013: for latest just visit http://www.iana.org )
RIR(NIC) Area Covered
AFRINIC Africa Region
APNIC Asia/Pacific Region
ARIN North America Region
LACNIC Latin America and some Caribbean Islands
RIPE NCC Europe, the Middle East, and Central Asia
each NIC has a home page where you can see its latest IP addr allocation/assignment list.
"whois" cmd lets you query the domain name in NIC registry
ASN = autonomous system numbers
Wikipedia is an already very good doc here but in my summary, an AS is just a big network of networks that are operated under one routing policy. AS and AS communicate using BGP(border gateway protocol). Obviously this is where you start seeing ISP as business. if you connect to ISP AS, you get to be connected to the rest of the internet.
ASN is just a 16-bit integer. 1-64511 are global ASNs assigned by IANA. 64512-65535 are private ASNs to be used within each ASN.
CIDR = classless inter-domain routing
class-A,B,C notion of IP addr allocation is not efficient cos class-B is fairly big for any organization and class-C is too small. so we just use subnet mask to more flexibly allcocate network-addr(aka prefix) and host-addr. VLNS (= variable length subnet masking)
Lets think about 220.127.116.11
Lets say RIR assigns a CIDR block 18.104.22.168/11 to some ISP. that ISP can then splits the address space and assigns a sub chunk 22.214.171.124/22 to some company which also does the split and assigns 126.96.36.199/24 to some group within the organization. then within the /24 name space, you have 188.8.131.52
===> this enables efficient routing based on CIDR scheme addr.
gTLD = generic top level domain (e.g. .com .net .org .biz .info )
ccTLD = country code TLD (e.g. .us .uk .me .tv .jp .tw .in)
sTLD = sponsored TLD (e.g. .xxx .mobi .cat .travel .jobs .tel .mail)
gTLD is literally generic and free for everyone. ccTLD has some conditions/restrictions. e.g. .jp is only available for people residing in japan, but many minor countries open up their ccTLD to seek foreign capital flow.
usually there is a limit, e.g. for .com <your_domain_name>.com => your domain name can be 3-63 chars.
- 2017-12-08 22:03:41 |
- Category : misc
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