Hello all,
after connecting to internet through Ethernet modem, whenever i check my IP address using

i get either of two ranges
one is :59.144.x.y
second is :203.101.a.b

What does it shows ???
plz. be a bit explanatory if required.

regards

It means that that is the address you're pulling from your ISP.

I didn't meant to ask that.

what i was intending to ask is:

1. Is it showing anything about the ISP servers....that how many he using or anything else...
2. Since everytime whether i get as 59. . . . or 203. . . , the first two octets remain the same. Does it means he is usnig class 'B' addressing scheme and his subnetmask is 255.255.0.0 ?

regards

one is a class A and two is a class C.

Not sure what your question is.

Your ISP assigns you a routable address, it buys(or is assigned). This has to be a unique address. That is probably the two ranges(depending on how big your ISP is, it may be the only ones they have)they use. You never, ever, ever use the subnet mask to determine class. When you get into subnetting and borrowing bits you can have a class B address with a subnet mask that looks like a class C. (think i got that in the correct order). Its still a class B.

This all works basically the same way a phone company works.

They buy phone numbers from 1-555-212-**** and 1-555-217-****, when you get a phone, they pull a number from this range so you will have a unique number. You just get new IP's more often than you get new phone numbers.

soule

Are you saying this on the basis of following convention :
1.x.x.x -> 126.x.x.x : Class A
128.x.x.x -> 191.x.x.x : Class B
192.x.x.x -> 223.x.x.x : Class C
223.x.x.x -> till last : Class D
( God knows about the Class E )

But someone told me that now this class convention has become obsolete and everything depends on the "subnet" mask value, b'coz we have started using CIDR.

regards

It is not clear what you are asking. Many ISPs and corporations own IP address spaces that are not contiguous or within the same class. Many use variable subnet masking. They even use non-contiguous masks, but we should not go there. That is done strictly for security purposes and becomes very confusing to decode if you do not already know the infrastructures.

There is nothing to prevent them from using different networks and subnetworks in the DHCP database. They can also use different databases that load share such that each successive client will get a different subnet.