what is the difference b/w CIDR AND VLSM?

Question Posted / guest

2 Answers
7927 Views
TCS, I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

what is the difference b/w CIDR AND VLSM?..

Answer / sandeep pawar

Classless Inter-Domain Routing (CIDR) is a method of
allocating IP addresses and routing Internet Protocol
packets.
It facilitates routing by allowing blocks of addresses to
be grouped into single routing table entries. These groups,
commonly called CIDR blocks, share an initial sequence of
bits in the binary representation of their IP addresses.
When emphasizing only the size of a network, terms like /20
are used, which is a CIDR block with an unspecified 20-bit
prefix.

A Variable Length Subnet Mask (VLSM) is a means of
allocating IP addressing resources to subnets according to
their individual need rather than some general network-wide
rule. Of the IP routing protocols supported by Cisco,
OSPF, Dual IS-IS, BGP-4, and EIGRP support "classless" or
VLSM routes.

Classless Inter-Domain Routing is based on variable-length
subnet masking (VLSM), which allows a network to be divided
into different-sized subnets. CIDR avoids wasting IP
addresses

Is This Answer Correct ?

12 Yes

0 No

what is the difference b/w CIDR AND VLSM?..

Answer / sheshdhar dueby

------------------------------------------------------------
--------------------

CIDR = Prefix length.

VLSM is taking a subnetted address and re-subnetting one of
the subnetted networks.

IE, if you have 192.168.10.0/27, you have networks:
192.168.10.0
192.168.10.32
192.168.10.64
192.168.10.96
etc.

You can take (for example) 192.168.10.32/27, and make it
192.168.10.32/29, thus Varying the Length of the Subnet
Mask. You can now have networks:
192.168.10.32
192.168.10.40
192.168.10.48
192.168.10.56

If we assume 192.168.10.64 is in use, as are all the
addresses that follow in the original /27 scheme, then you
have to stop there. If the .64 address scheme is not being
used you can keep going with the smaller subnet size until
you reach an address that is in use. Obviously you can't
duplicate addresses...

Is This Answer Correct ?

2 Yes

1 No

Post New Answer

More Networking Administration Interview Questions

hi , I m Ajay . i'v done my Bsc in 1997. my age 35 yrs . i'v working knowledge in computer maintinance and installation . it is possible to get job in call center as technical support or system management in companies . i'v also done redhat enterprise linux 4. (RHEL4) course.

4 Answers

PPP is an extension of ? a. FRAME RELAY b. SDLC c. HDLC d. LAPB

1 Answers

Can you please explain the difference between hub and a switch?

0 Answers

Which program displays program number, version, protocol, port number, service, and owner of RPC service (root) ?

1 Answers

Explain the maximum length allowed for a utp cable?

0 Answers

How to a software deploy in sales OU?

1 Answers

what are the types protocols?