In this article I describe the function of wildcard mask in networking. Wildcard mask is invert value of subnet mask. The length of wildcard mask is similar to subnet mask. The role of wildcard mask in networking is just opposite to the subnet mask. Wildcard mask in networking used to filter the incoming and outgoing traffic through firewall.
Wildcard mask in networking used to create access lists in routers. Router check the data packets for filtering according to wildcard mask in networking. The router focus on the digits of wildcard mask rather than entire IP address. We can say wildcard mask in networking help to select the IP address for allow or deny in the network according to ACLs.
Wildcard mask in networking explained
A wildcard mask is 32 bits long binary address. Wildcard mask is just inverted value of subnet. We know the subnet helps the router for flow the data packets to destination IP address. Wildcard masks provides the selection of network addresses to be used. Wildcard mask also used to group the different subnets together for filtering of traffic. Wildcard masks used to create the ACLs in router.
We know that the subnet used to define the LAN. Wildcard masks are mostly used to create the access control lists and with OSPF routing protocol. The bits 0 and 1 of subnet mask replaced by inverted digits for wildcard mask in networking. In subnet mask the digit 1 are ignored and digit 0 considered. In wildcard mask the digit 0 ignored and digit 1 considered for filtering of traffic. Actually the wildcard mask allow router to match the IP address of data packet with access list.
Example of wildcard mask in networking
In a LAN the subnet mask defines the network for communication. Suppose i have a network with network ID 192.168.1.0/24. All devices lies in the network 192.168.1.0/24 can communicate with each other. But what if i want to deny only single network and allow all other networks. For example I want to allowed all network ID packets in my network except 192.168.1.0/24. in this case i use the wildcard mask to deny all traffic from the network 192.168.1.0/24.
subnet mask for network 192.168.1.0/24 is 255.255.255.0. As explained in above paragraph the wildcard mask is inverted value of subnet mask so the wildcard mask for network 192.168.1.0/24 will be 0.0.0.255. The command to deny all data from network 192.168.1.0/24 be like #deny 192.168.1.0 0.0.0.255.
Where to use the wildcard mask in network?
As mentioned above the wildcard mask is use to deny the traffic via router. Wildcard mask can be used in a large network to allow free traffic flow between routers. The example of wildcard mask is OSPF protocol.
I described the wildcard mask in network in this article hope you understood the use of wildcard mask in network. For any query or suggestion on this article contact us or drop a comment below. .
