How many bits in ip

192.168.10.0/25 25bit
10.10.10.0/30 30 bit
172.16.1.0/27 27 bit

id
192.168.10.0
10.10.10.0
172.16.1.0

max host with 0th subnet
192.168.10.0/25 126
10.10.10.0/30 2
172.16.1.0/27 30

first ip
Net A 192.168.10.0/25 -> 192.168.10.2
Net B 10.10.10.0/30 ->  10.10.10.2
Net C 172.16.1.0/27 -> 172.16.1.2

last ip
Net A 192.168.10.0/25 -> 192.168.10.127
Net B10.10.10.0/30 -> 10.10.10.3
Net B 172.16.1.0/27 -> 172.16.1.31

broadcast id
Net A 192.168.10.0/25 -> 192.168.10.1
Net B 10.10.10.0/30 -> 10.10.10.1
Net C 172.16.1.0/27 -> 172.16.1.1101400

subnet mask
Net A 192.168.10.0/25 -> 255.255.255.0
10.10.10.0/30 -> 255.0.0.0
172.16.1.0/27 -> 255.255.0.0


cli erase startup-config
Switch>enable
Switch#erase startup-config
Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]
[OK]
Erase of nvram: complete
%SYS-7-NV_BLOCK_INIT: Initialized the geometry of nvram
Switch#exit
Switch con0 is now available
Press RETURN to get started.


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




         --- System Configuration Dialog ---

Would you like to enter the initial configuration dialog? [yes/no]: y

At any point you may enter a question mark '?' for help.
Use ctrl-c to abort configuration dialog at any prompt.
Default settings are in square brackets '[]'.


Basic management setup configures only enough connectivity
for management of the system, extended setup will ask you
to configure each interface on the system

Would you like to enter basic management setup? [yes/no]: y
Configuring global parameters:

  Enter host name [Router]: R1

  The enable secret is a password used to protect access to
  privileged EXEC and configuration modes. This password, after
  entered, becomes encrypted in the configuration.
  Enter enable secret: cisco123

  The enable password is used when you do not specify an
  enable secret password, with some older software versions, and
  some boot images.
  Enter enable password: ciscocon123

  The virtual terminal password is used to protect
  access to the router over a network interface.
  Enter virtual terminal password: ciscovty123
Configure SNMP Network Management? [no]:n

Current interface summary

Interface              IP-Address      OK? Method Status                Protocol

FastEthernet0/0        unassigned      YES manual administratively down down

FastEthernet1/0        unassigned      YES manual administratively down down

Serial2/0              unassigned      YES manual administratively down down

Serial3/0              unassigned      YES manual administratively down down

FastEthernet4/0        unassigned      YES manual administratively down down

FastEthernet5/0        unassigned      YES manual administratively down down

Enter interface name used to connect to the
management network from the above interface summary: FasEthernet0/0
Invalid interface
Enter interface name used to connect to the
management network from the above interface summary: FastEthernet0/0

Configuring interface FastEthernet0/0:
  Configure IP on this interface? [yes]: y
    IP address for this interface: 192.168.10.3
    Subnet mask for this interface [255.255.255.0] : 255.255.255.0

The following configuration command script was created:

!
hostname R1
enable secret 5 $1$mERr$5.a6P4JqbNiMX01usIfka/
enable password ciscocon123
line vty 0 4
password ciscovty123
!
interface FastEthernet0/0
 no shutdown
 ip address 192.168.10.3 255.255.255.0
!
interface FastEthernet1/0
 shutdown
 no ip address
!
interface Serial2/0
 shutdown
 no ip address
!
interface Serial3/0
 shutdown
 no ip address
!
interface FastEthernet4/0
 shutdown
 no ip address
!
interface FastEthernet5/0
 shutdown
 no ip address
!
end

[0] Go to the IOS command prompt without saving this config.
[1] Return back to the setup without saving this config.
[2] Save this configuration to nvram and exit.

Enter your selection [2]: 2
Building configuration...
[OK]
Use the enabled mode 'configure' command to modify this configuration.


Press RETURN to get started!


%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up

%LINK-5-CHANGED: Interface FastEthernet1/0, changed state to up

%LINK-5-CHANGED: Interface FastEthernet1/0, changed state to administratively down

%SYS-5-CONFIG_I: Configured from console by console


R1>enable
Password: 
R1#config term
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#interf
% Incomplete command.
R1(config)#interf Serial2/0
R1(config-if)#ip 10.10.10.2
                 ^
% Invalid input detected at '^' marker.
	
R1(config-if)#config ip
%Invalid hex value
R1(config)#config ip 10.10.10.2
                     ^
% Invalid input detected at '^' marker.
	
R1(config)#config ip10.10.10.2
%Invalid hex value
R1(config)#interface Serial2/0
R1(config-if)#sho ip
                ^
% Invalid input detected at '^' marker.
	
R1(config-if)#ip address 10.10.10.2
% Incomplete command.
R1(config-if)#ip address 10.10.10.2 255.0.0.0
R1(config-if)#exit
R1(config)#exit
R1#
%SYS-5-CONFIG_I: Configured from console by console

R1#exit









R1 con0 is now available






Press RETURN to get started.













R1>ping r2
Translating "r2"...domain server (255.255.255.255)
% Unrecognized host or address or protocol not running.

R1>R1>
R1>enable
Password: 
Password: 
R1#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#interface FastEthernet0/0
R1(config-if)#
R1(config-if)#exit
R1(config)#interface Serial2/0
R1(config-if)#R1(config-if)#ex
R1(config)#interface Serial2/0
R1(config-if)#ip address 10.10.10.2 255.0.0.0
R1(config-if)#no shut

R1(config-if)#
-----------------------------------------------------------------------------------




