How Cloud Computing can make a small company look big

Using Cloud Computing can make you company look larger than what it really is. If a small company wants to have a website they can. There are many different companies that will host your website and if you need them to design it they will do that also. It is also nice to have your domain and email address match. This allows a company in a small town to reach all over the world for a small cost. The company can have a toll free fax line for less than a basic phone line.  With this fax line you can send faxes from your computer or receive faxes to you email or check it on the internet. With this fax system you can check your faxes as long as you have access to the internet or check you email.  You can also have your faxes sent to more than one email address. Most companies use a Post Office Box that does not tell you the size of the company.

When a small business is just starting out, they want to look bigger that what they are. These are just a few things that they can do to reach more people and look larger than what they are for a small coast. When a company large or small looks professional customers feel secure about doing business with that company.

RIPv2 vs EIGRP

RIPv2 improves upon RIPv1 with the ability to use VLSM, with support for route authentication, and with multicasting of route updates. RIPv2 supports CIDR. It still sends updates every 30 seconds and retains the 15-hop limit; it also uses triggered updates. RIPv2 still uses UDP port 520; the RIP process is responsible for checking the version number. It retains the loop-prevention strategies of poison reverse and counting to infinity. On Cisco routers, RIPv2 has the same administrative distance as RIPv1, which are 120. Finally, RIPv2 uses the IP address 224.0.0.9 when multicasting route updates to other RIP routers. As in RIPv1, RIPv2 will, by default, summarize IP networks at network boundaries. You can disable auto summarization if required.

 EIGRP in the early 1990s as an evolution of IGRP toward a more scalable routing protocol for large internetworks. EIGRP is a classless protocol that permits the use of VLSMs and that supports CIDR for the scalable allocation of IP addresses. EIGRP does not send routing updates periodically, as does IGRP. EIGRP allows for authentication with simple passwords or with MD5. EIGRP auto summarizes networks at network borders and can load-balance over unequal–cost paths. Packets using EIGRP use IP protocol 88. Only Cisco routers can use EIGRP.

EIGRP is an advanced distance-vector protocol that implements some characteristics similar to those of link-state protocols. Some Cisco documentation refers to EIGRP as a hybrid protocol. EIGRP advertises its routing table to its neighbors as distance-vector protocols do, but it uses hellos and forms neighbor relationships as link-state protocols do. EIGRP sends partial updates when a metric or the topology changes on the network. It does not send full routing-table updates in periodic fashion as do distance-vector protocols. EIGRP uses DUAL to determine loop-free paths to destinations. This section discusses DUAL.

Remember RIPv2 is for small network and EIGRP is for large networks.  RIPv2 update every 30 sec and EIGRP only update when there is a change saving on bandwidth

Layer 3 protocols (Network Layer)

IS-IS-Intermediate System-to Intermediate System is a routing protocol designed to move information efficiently within a computer network, a group of physically connected computers or similar devices. It accomplishes this by determining the best route for datagrams through a packet-switched network. The protocol was defined in ISO/IEC 10589:2002 as an international standard within the internet standard (OSI) reference design.

OSPF- Open Shortest Path First is an adaptive routing protocol for internet protocol (IP) networks. It uses a link state routing algorithm and falls into the group of interior routing protocols, operating within a single autonomous system (AS). It is defined as OSPF Version 2 in  for Ipv4. There is an  updates for Ipv6 that is specified as OSPF Version 3

BGP- Border Gateway Protocol is the protocol backing the core routing decisions on the internet. It maintains a table of IP networks or 'prefixes' which designate network reach ability among autonomous systems

RIPv1 Routing  Information Protocol is a dynamic routing protocol  used in local and wide area networks

Easy Subneting

128      64        32        16        8          4          2          1

To calculate the number of hosts or the number of networks for a given subnet mask, use the following formula:

2^(number of bits used) - 2 = number of networks/hosts (The ‘^’ means ‘raised to the power of’.)

So, given the fact that we have borrowed 2 bits to extend our network, we have 2^2 - 2 = 2 networks (remember, we are excluding the all 1 and all 0 networks).

We have 14 bits left to describe the hosts on each network; therefore we have 2^14 - 2 = 16,382 hosts per network (remember we are excluding host addresses with all 0s or all 1s).

The value of the lowest order bit in the subnet mask tells you two things: a) it tells you the first network ID for the subnets created by the extended subnet mask, b) it tells you the value that you can add to one network ID to arrive at the next possible network ID.

Let’s take our example extended subnet mask of 255.255.192.0. The 3rd octet expressed in binary with the decimal equivalents is:

128 64 32 16 8 4 2 1

1 1 0 0 0 0 0 0

The value of the lowest order bit is 64. Therefore, our first network ID is 172.16.64.0/18. The next and last network ID is 172.16.128.0/18 (64 + 64 = 128)

VLAN

By default, all switches are configured to be VTP servers. This configuration is suitable for small-scale networks in which the size of the VLAN information is small and the information is easily stored in all switches (in NVRAM). In a large network, the network administrator must make a judgment call at some point, when the NVRAM storage that is necessary is wasteful because it is duplicated on every switch. At this point, the network administrator must choose a few well-equipped switches and keep them as VTP servers. Everything else that participates in VTP can be turned into a client. The number of VTP servers should be chosen in order to provide the degree of redundancy that is desired in the network.

VLAN is a software concept, identifiers and configurations for a VLAN must be properly prepared for it to function as expected. Frame coloring is the process used to ensure that VLAN members or groups are properly identified and handled. With frame coloring, packets are given the proper VLAN ID at their origin so that they may be properly processed as they pass through the network. The VLAN ID is then used to enable switching and routing engines to make the appropriate decisions as defined in the VLAN configuration.If the VLAN is not properly configured that part of the network will be down.

RIPv1 vs RIPv2

The main difference between RIPv1 and RIPv2 is classless routing. RIPv2 incorporates the addition of the network mask in the update to allow classless routing advertisements. This is extremely important for the flexibility needed to efficiently utilize network assignments for an ever-shrinking pool of IP addresses.

There are other differences, as well. In RIPv2, the destination address for the updates is multicast, instead of broadcast, as in RIPv1. This reduces the burden on the network devices that do not need to listen to RIP updates. With broadcast, every device on the broadcast domain must at least open the IP packet and process the initial information to determine relevance. With multicast addressing, if a device needs that information, it will listen to that specific address. If it does not need the RIP information, it does not have to process the multicast address. The multicast address RIPv2 sends to is 224.0.0.9.

NAT

With the explosion of the Internet and the increase in home networks and business networks, the number of available IP addresses is simply not enough. The obvious solution is to redesign the address format to allow for more possible addresses. This is being developed (called IPv6), but will take several years to implement because it requires modification of the entire infrastructure of the Internet.

­ This is where NAT comes to the rescue. Network Address Translation allows a single device, such as a router, to act as an agent between the Internet ( "public network") and a local (or "private") network. This means that only a single, unique IP address is required to represent an entire group of computers.

NAT also blocks your private network from the world.