cisco-technology.blogspot.com
CISCO Technology: IP Subnetting
http://cisco-technology.blogspot.com/2009/07/ip-subnetting.html
Sunday, July 26, 2009. Number of Hosts; represent the number of ZERO in the entire 32 bit subnet. ZERO usually follows from RIGHT to LEFT, e.g. 11111111.11111111.11111100.00000000. Hence a simple subtraction of the given subnet mask from 32 (as 32 represent all bits to be 1) will give us the number of hosts in that subnet. To find the number of hosts in /25 subnet. Subtract 32-25 = 7; This represent the number of ZERO is a subnet. In this example there are 7 ZERO. 2 7 = 128. 32-21 = 11;. 2 11 = 2048.
cisco-technology.blogspot.com
CISCO Technology: July 2009
http://cisco-technology.blogspot.com/2009_07_01_archive.html
Sunday, July 26, 2009. Number of Hosts; represent the number of ZERO in the entire 32 bit subnet. ZERO usually follows from RIGHT to LEFT, e.g. 11111111.11111111.11111100.00000000. Hence a simple subtraction of the given subnet mask from 32 (as 32 represent all bits to be 1) will give us the number of hosts in that subnet. To find the number of hosts in /25 subnet. Subtract 32-25 = 7; This represent the number of ZERO is a subnet. In this example there are 7 ZERO. 2 7 = 128. 32-21 = 11;. 2 11 = 2048.
lan-technology.blogspot.com
LAN Techonology: HSRP
http://lan-technology.blogspot.com/2008/07/hsrp-is-cisco-proprietary-protocol.html
Welcome to IT Networking Guide. Saturday, July 5, 2008. Protocol developed to allow several routers or multilayer switches to appear as a single gateway IP address for internal hosts. HSRP active router election is based on a priority value (0 to 255). That is configured on each router in the group. Default priority is 100. To the multicast destination 224.0.0.2 using UDP port 1985). If hellos are missed for the duration of the holdtime timer (default 10 seconds. Hello message conveys router's HSRP prior...
lan-technology.blogspot.com
LAN Techonology: July 2008
http://lan-technology.blogspot.com/2008_07_01_archive.html
Welcome to IT Networking Guide. Sunday, July 6, 2008. Virtual LANs (VLANs) enable network managers to group users logically rather than by physical location. Enters global configuration mode. Switch(config)# interface {gigabitethernet fastethernet} card/subcard/port.subinterface. Enters subinterface configuration mode. Specifies ISL encapsulation for the Ethernet frames sent from this subinterface, with a header that maintains the specified VLAN ID between network nodes. Switch# copy system:running-confi...
cisco-technology.blogspot.com
CISCO Technology: July 2008
http://cisco-technology.blogspot.com/2008_07_01_archive.html
Tuesday, July 29, 2008. Interface subcommand tells the router to forward broadcasts packets which received on the interface to the destination address specified. In general router stops all the broadcast packets, but there are some instance when we need to allow broadcast packet, such-as. Broadcast should be allowed to get IP address for Host or IP Phone while booting up. Broadcast should be allowed for UDP packets. When a workstation that is a DHCP client boots up, it sends out a. When multiple helper-a...
lan-technology.blogspot.com
LAN Techonology: June 2008
http://lan-technology.blogspot.com/2008_06_01_archive.html
Welcome to IT Networking Guide. Saturday, June 28, 2008. STP (Spanning Tree Protocol) 802.1D. STP is used to prevent L2 loops and at the same time provide redundancy. STP prevents loops in the network by assigning either the blocking or forwarding state on the ports. Hence with these two states STP provide redundancy as well as preventing loops in the network. This mechanism guarantees that there is one and only one active path between two network devices. STP uses 3 types of timers. Root Bridge ID and S...