Changing Your IP Address

The book I read to research this post was How To Change My IP Address in 15 Minutes by Morgan Freecan which is a very good book that I read at kindle unlimited. I don’t normally read books that are this short but this book is on a niche subject. The book is around 25 pages so is quite short. It is about changing your IP or Internet Protocol address which is the numeric address that identifies your computer or/and router over the internet. It might surprise you that this is unlikely to be a static address and can be changed. Of course there can be nefarious motives to this like if you are banned from a website which will normally block the IP address. Other people might want to change it on a regular basis for security. In Windows 7 you can go into the start menu select the Run option and enter cmd to find your IP number. It can be changed with in a browser like Firefox or Chrome. Alternatively it can be changed with a Proxy Server or Virtual Private Network. There is also free software called Storm Shield that will do this. One exception is if you have a long term business account with an ISP they might have assigned you a long term IP which can’t be changed. Of course there is more details on all this in the book. I very much enjoyed reading this and definitely recommend it. The author has used his imagination to come up with an usual and very interesting subject.

 

TCP/IP Part 5

This is the final installment in my series of blog posts on TCP/IP which are based on what I learn doing an Infinite Skills training video. In this blog post I am mostly looking at wireless networking with a little on IPV4 & IPV6. There is a program called H Ping that is a good packet creator software. There is a type of network attack called a Fraggle attack and is similar to a smurf attack except the former uses UDP where as the latter uses TCP. Both types try to flood the server on a large network with loads of data from every client computer. Both types of attack are very rare nowadays because network hardware has advanced to a point where they are well prepared for it. 802.11 is the protocol for wireless networking which comes in versions, a, b, g, n & ad. Funnily enough b is the slowest and if you broadcast on 5 GHz and not 2.4 GHz you are less likely to find a signal clash with other devices. inSSiDer 2 is a windows program that lets you set up a wireless connection easily. Generally any wireless device will scan for available networks when you set it up and let you choose one. WPA is better than WEP for encrypting documents to send by wireless and there is a WPA 2 which is better still. If you send unencrypted messages anyone with a wireless receiver can read them. WPA & WPA 2 use a shared key for the messages to be read going both ways. A network should always be password and the users having their own passwords. IPV6 uses 8 groups of hexadecimal numbers and is far superior to it’s parent IPV4. IPV4 is in danger of not supporting enough computers as each has to be individually numbered and it only reaches around 4 billion. IPV6 is highly unlikely to ever reach its limits which is a huge number. IPV4 uses multi-casting to send the same message to several recipients. IPV6 does it with in the program. It also lets you send much bigger amounts of data although this is limited by your broadband connection.

TCP/IP Part 4

This the latest installment in my series of blog posts on TCP/IP and based on what I learnt from a video course by Infinite Skills. SMTP which stands for simple mail transfer protocol & POP 3 which stands for post office protocol are the 2 main protocols used with e-mail. If you do a capture in wireshark you will often see SMB or sender message block. These transfer text and convey file information and are very common on most computers. Website addresses are normally conveyed in HTTP or DNS, both of which convert the URL into something the computer can understand. There is also something called TLS which the part of the website address that is something like .com or .net. Most countries have there own add on bits to the website address similar to .com. TCP/IP is a very old protocol developed for use on the Arpanet etc and probably because the military developed it, it’s very resilient and still in use despite many changes. TCP/IP is very much the most used protocol on networks and individual computers. I remember if you had to install a modem on a NT4 operating system you had to install TCP/IP on the system before.

 

TCP/IP Part 3

This is another installment in my series of blog posts on TCP/IP based on the Infinite Skills course I have been studying. Last time I did look at ICMP and there is something called ICMP attacks. One method is to flood a server with large files coming from lots of remote hosts and of course you put some kind of virus on these hosts and hijack their connection. Another kind of attack called smurfing is to send a message to every host on a large network and getting them to flood the server with data. Most networks nowadays have hardware that can deal with these kinds of attacks so they are very rare but at one time they were quite common. In sending a message over a network there is something called a 3 way handshake. With this the sending host sends a synchronize request then the receiving host sends an acknowledge request then the sending host sends a get request followed by the data. There is an option particularly on wireless networks as to whether you want the file fragmented and you should select yes unless there is a very good reason not to because more often than not if the file exceeds a certain size it won’t get sent and will be returned to the sender. There are thousands of ports on a computer and these are channels not actual ports and it is often a good idea to at least close certain ones of these and monitor which ones your computer is using as viruses can gain access to your computer or network via these. There is a UDP or user datagram protocol which is relatively high speed and is useful if the sequence something is sent in is unimportant. DNS is domain name server and refers to the internet address of a server on a network. HTTP or hypertext transfer protocol is also very similar. The session layer in the OSI model as well as other things replaces lost data if it’s retrievable if it’s lost in transit on a network. Encryption is also on this layer. Checksum checks a file for its size both before and after it’s sent on a network and gives an error message if both aren’t the same size. The RTS protocol is used to stream video and audio. If something is encrypted and sent on a network the sending host will normally send an SSL or secure socket layer and the receiving host will reply with a TLS or transport layer security signal.

 

TCP/IP Part 2

This is the next blog post in my series on TCP/IP based on the Infinite Skills course. First of all I’m looking at IP addresses. These are numbered in 4 groups from 0 to 255 and can be made up in 7 digits. Computers count in binary where 1 indicates a circuit in on and 0 off. Networks are numbered according to these numbers and the series

255.255.255.0 indicates a subnet which is where a network is subdivided. There is also regions of these numbers for things like broadcasts and multicasts and the further to the left the number is divided generally the bigger the network. There are also various protocols some of which I’m going to look at. ICMP is information control management protocol. It gives generally diagnostic information about a host. DHCP is dynamic host control protocol and is a non-static numbering system for hosts on a network as opposed to the static numbering of boot protocol. ARP is address resolution protocol and is when a sending host tries to find a recieving host and out several digits which are answering similarly. You do see ARP spoofing because there is no authenticode as such any host can send any ARP signal with the right software like Kane And Able which is a software program that will do the job. OSPF is open shortest path first and is a protocol that sends information about where a receiving host is and the shortest route that can be used with the least number of hops between routers. BGP is border gateway protocol and is the location of the receiving host sent to the sending host and also there are keep alive to show both hosts are still active during message transmission. I’ll be doing another installment tomorrow.

 

TCP/IP Part 1

This is a new series of blog posts on TCP/IP which is transmission control protocol internet protocol and is based on the Learning TCP/IP course by Infinite Skills which I am doing. I will be doing a post on a daily basis. TCP/IP is a suite of internet protocols which are basically rules for how computers and their networks communicate over the internet. There are other protocols as well as TCP/IP such as IPX & Appletalk but TCP/IP is the most widely used. The origins of the internet started with the ARPANET the basic backbone of which was constructed in 1967 and was a network for the Department Of Defense in America and was built in a decentralized way to survive a nuclear attack. There were other networks built soon after and around that time in particular networks for universities and scientists to communicate with one another. Initially there was TCP which was a protocol for networks and the IP part came later. This course looks quite a bit at wireshark which is a wireless packet capture and analysis program. It’s free to download and contains a filter to look at certain packets of a particular type. The filter box goes red to show it’s incomplete and turns green when you enter a complete search. You can right click on a packet and choose an option to search for packets of the same type. In the filter box you enter the equals sign twice to specify a search criteria because there is always the chance the equals sign might be part of the search criteria. You can search for a type of transmission like tcp or ip and ip would cover just about every transmission type so would be useless. There is something called the OSI model which consists of 7 modules which are Physical, Data Link, Network, Transport, Session, Presentation & Application. These modules are called layers and the lowest layer is Physical and the one data from the internet initially comes through & the highest layer is Application which works directly at a software level including your web browser. Data goes from one layer to the next all the way up and down this model. Different types of protocol work with different layers ie HTTP works with Application & TCP works with Transport. There are discrepancies about which protocols work with Session which isn’t an exact layer. There is also a TCP model which works similar to the OSI model although the top and bottom module incorporate several layers from the TCP model.

 

 

Networking & Network Access Protection

The book I read to research this post was Networking & Network Access Protection by Joseph Davies et al which is an excellent book although I wouldn’t recommend it to people new to computing also I bought it from amazon.

I thought I’d write a bit about the tunnel tag. It’s a vendor specific attribute or VSA  & is used with RADIUS wireless networking. The value you choose for tunnel tag is used for all RADIUS properties used in that policy. This identifies them as belonging to the same tunnel. A tunnel tag is not always required & is dependent on the vendor for your switch or access point.

More Networking

A buzzword being passed around the computing world is cloud computing and while how it works is less important than how a network works one thing that should concern businesses is that they are passing the responsibility of looking after their data to another party. They should always have a separate copy of their data offline and really offsite as well. Although storing data isn’t the only function of cloud computing there is things like accounting and word processing that can be done on the cloud but if the connection is down. You do need some kind of back up applications. One thing the cloud does remove is the need for even small computers to have massive amounts of storage and in some cases even the network administrator doesn’t know what they have running. Apparently only 6% of available storage is used. Huge companies that are connected to web services are adding huge amounts of storage to their networks. Microsoft is adding upto 35,000 servers every month. Cloud computing is set to expand and a lot of people think it may be more secure storage with large companies who have bigger budgets than small businesses and can afford the latest technology in terms of fighting cyber crime and at the end of the day if it becomes news that their storage networks are insecure they stand to lose a lot of business.

 

More TCP/IP

The book I read to research this post was TCP/IP for Dummies 6th edition by Candace Leiden et al which is an excellent book which I got from kindle. TCP/IP stands for transmission control protocol internet protocol and is a collection of protocols for the internet. The original internet was called the ARPANET and was built to withstand a nuclear attack, this meant decentralising it so that if one part went down it would continue to function. The US department of defence originally controlled the ARPANET. Later universities started using the internet to keep abreast of each others research. It’s interesting that google has over a thousand servers worldwide and although at one time their response time was 1 second that was considered too slow and now it is a tiny fraction of that.

With the popularity of VOIP or voice over internet protocol or phone calls via a pc which often use skype. Although skype will scramble calls making it impossible to hack there is a free program called VOMIT which will enable you to listen in to unscrambled calls. It has even been known for people to post other peoples private calls on the internet.