Home | Windows | Network | Interview Questions | Database | Virtualization | Knowledge Base | Contact Us

Home Links

Windows Home

Network Home

Database Home

KB Home

Interview Ques.

Network Int. Q & A

Windows Int. Q & A

SQL Int. Q & A

Knowledge Base.

Cisco VOIP

Windows 2003 KB

Windows 2008 KB

Win 2003 - IIS 6.0

SQL Failover Cluster

Group Policy Guide


CCNA - Topics

CCNA - Others

IP Addressing








IP Sec

CCNA Others


CIDR Stands for classless inter domain routing. It helps in preventing the wasting of IP address. With CIDR, a single IP address can be used to designate many unique IP addresses. A CIDR IP address looks like a normal IP address except that it ends with a slash followed by a number, called the IP network prefix. Eg:

CIDR Notation

CIDR specifies an IP address range using a combination of an IP address and its associated network mask.

CIDR notation uses the following format - xxx.xxx.xxx.xxx/n

Where n is the number of (leftmost) '1' bits in the mask.

For example:

For class A ..Default subnet mask is so CIDR notation is /8

For class B..Default subnet mask is so CIDR notation is /16

For class C..Default subnet mask is so CIDR notation is /24


CIDR and IP Address Aggregation:

IP Address Aggregation means that several networks can be spanned by a single routing entry.

Our router needs to route traffic for six separate networks through the same gateway
(IP address

ip route

ip route

ip route

ip route

ip route

ip route


Without CIDR, our routing table would need to maintain a separate entry for each of the six individual networks.

CCNA Overview Page

HTML Comment Box is loading comments...

Designed by TechieBird