How To Trace An Email

What is an email header?

Each email you receive comes with headers. The headers contain information about the routing of the email and the originating IP of the email. Not all emails you receive can be traced back to the originating point and depending on how you send emails determines whether or not they can trace the email back to you. The headers don't contain any personal information. At most, you can get the originating IP and the computer name that sent the email. The originating IP can be looked up to determine from where the email was sent. IP address location information DOES NOT contain your street address or phone number. It will most likely determine the city and the ISP the sender used.

How do I get the email header?

Each email program will vary as to how you get to the email options. I'll cover the basics...the rest is up to you.

• Outlook

Right click the email while it's in the inbox and choose Message Options. A window will open with the headers in the bottom of the window.

• Windows Live Mail

Right click the email while it's in the inbox, choose Properties, then click the Details tab.

• GMail

Open the email. In the upper right corner of the email you'll see the word Reply with a little down arrow to the right. Click the down arrow and choose Show Original.

• Hotmail

Right click the email in the inbox and choose View Message Source.

• Yahoo!

Right click the email in the inbox and choose View Full Headers.

You can see that no matter the email program, the headers are usually just a right click away.

I've got the header, now what?

Usually the first IP listed is where the email originated. There are exceptions to this. You'll have to look at the information logically to deduce the originating IP.

Can any email be traced?

Yes and No. For example, someone who sends an email to your hotmail account shows in the X-Originating IP section of the headers. However, someone who sends you an email from GMail can ONLY be traced back to the GMail servers.

- JMD COMPUTER INDIA

Source: http://www.whatismyip.com/faq/how-to-trace-an-email.asp

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Router Support

A lot of users in the What Is My IP Forum will ask us for help with their router. Unless it's one we specifically own, our help will be limited. The links below are to provide users a way to find their users manual on their Routers Manufacturer's site. If you've still got questions, you can ask them in the Router Configuration Forum.

• Belkin
• Buffalo
• D-Link
• Linksys
• NetGear

- JMD COMPUTER INDIA

Source: http://www.whatismyip.com/faq/router-support.asp

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What Is MAC Cloning?

MAC cloning can only be done at your router providing it has those capabilities. Most ISPs assign their IPs based on the MAC address in your equipment. If the MAC address of your router is 00-11-22-33-44-55 and you connect to your ISP, the DHCP server records your MAC and assigns an IP. If you disconnect from the ISP, you lose your IP address. The next time you connect, the DHCP server sees your MAC, looks to see if it has assigned an IP address to you before. If it has and the lease time has not expired, it will most likely give you the same IP address you had before disconnecting. Why clone a MAC address? New MAC address most likely equals new IP. How to clone your MAC and if your router has this feature is dependent on the router itself. You’ll need to find the instructions on the manufacturer’s website. Check out our Router Support page to get started.

- JMD COMPUTER INDIA

Source: http://www.whatismyip.com/faq/what-is-mac-cloning.asp

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What is a MAC address?

A MAC address is a physical hardware address assigned to each device that has the capability of connecting to a network. The internet is nothing more than a large network. The MAC address is something that is assigned in the chip on the device and is not something the user can change.

- JMD COMPUTER INDIA

Source:http://www.whatismyip.com/faq/what-is-a-mac-address.asp

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UNIX IP Commands

Display Current Config for all NIC's: ifconfig

Display Current Config for dc0: ifconfig dc0

Assign multiple IP's: ifconfig dc0:0 192.168.1.2

Assign second IP: ifconfig dc0:1 192.168.1.3

Disable network card: ifconfig dc0 down

Enable network card: ifconfig dc0 up

Assign IP/Subnet: ifconfig dc0 inet 192.168.1.2 netmask 255.255.255.0

Assign Gateway: route delete default && route add default 192.168.1.1

You MUST be at the ROOT user to make/save any changes. You will need to save your changes in the /etc/rc.conf file. Network cards are referred to as dc0, dc1, dc2, etc based on their position on the PCI bus.

Special thanks to Romanov Sergey Vladimirovich from Moscow for the UNIX command.

- JMD COMPUTER INDIA

Source: http://www.whatismyip.com/faq/unix-ip-commands.asp

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Linux IP Commands

Display Current Config for all NIC's: ifconfig

Display Current Config for eth0: ifconfig eth0

Assign IP: ifconfig eth0 192.168.1.2

Ping: ping -c 3 192.168.1.1

Assign multiple IP's: ifconfig eth0:0 192.168.1.2

Assign second IP: ifconfig eth0:1 192.168.1.3

Disable network card: ifconfig eth0 down

Enable network card: ifconfig eth0 up

View current routing table: route "or" route -n

View arp cache: arp "or" arp -n

Assign IP/Subnet: ifconfig eth0 192.168.1.2 netmask 255.255.255.0

Assign Default Gateway: route add default gw 192.168.1.1

Trace Route: traceroute www.whatismyip.com

Trace Path: tracepath www.whatismyip.com

DNS Test: host www.whatismyip.com

Advanced DNS Test: dig www.whatismyip.com

Reverse Lookup: host 66.11.119.69

Advanced Reverse Lookup: dig -x 66.11.119.69

You MUST be at the ROOT user to make/save any changes. Linux users, your distribution will determine the location of your network config file which will need to be updated and saved in order for the changes to remain in effect after rebooting. Network cards are referred to as eth0, eth1, eth2, etc based on their position on the PCI bus.

Special thanks to Gergely for the Linux commands!

- JMD COMPUTER INDIA

Source: http://www.whatismyip.com/faq/linux-ip-commands.asp

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DOS / Windows IP Commands

Display Connection Configuration: ipconfig /all

Display DNS Cache Info: ipconfig /displaydns

Clear DNS Cache: ipconfig /flushdns

Release All IP Address Connections: ipconfig /release

Renew All IP Address Connections: ipconfig /renew

Re-Register the DNS connections: ipconfig /registerdns

Change/Modify DHCP Class ID: ipconfig /setclassid

Network Connections: control netconnections

Network Setup Wizard: netsetup.cpl

Test Connectivity: ping www.whatismyip.com

Trace IP address Route: tracert

Displays the TCP/IP protocol sessions: netstat

Display Local Route: route

Display Resolved MAC Addresses: arp

Display Name of Computer Currently on: hostname

Display DHCP Class Information: ipconfig /showclassid

- JMD COMPUTER INDIA

Source: http://www.whatismyip.com/faq/dos-windows-ip-commands.asp

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What Is DHCP?

Dynamic Host Configuration Protocol

In simple terms, DHCP determines if your IP is static or dynamic.

DHCP is controlled by a DHCP server. Your router can be a DHCP server...and if you're on a home network, it most likely is your DHCP server.

I know this might be confusing because the word dynamic is in the term, but just because you have DHCP enabled on your computer doesn't mean you can't be assigned a static IP. DHCP enabled on your computer simply means you're letting a DHCP server assign its IP. Having it enabled DOES NOT mean it's a DHCP server.

A true DHCP server (not your Linksys router) gives the LAN Admin a ton of control with IP assigning.

Ever print to a network printer? Ever wonder how that printer keeps its network assignment? Probably through DHCP. Each network device has a MAC address. You can assign a static IP at the DHCP server to a specific MAC address. This allows the network printer to always get the same IP even after it reboots and without assigning the IP at the printer. If you print the network configuration at the printer, it will probably tell you that DHCP is enabled and no static IP is assigned. That's because the IP assignment is handled at the DHCP server.

Your ISP has a DHCP server. They can assign IPs by modem MAC addresses. When your modem comes online, it communicates to the network indicating it is looking for an IP address. The DHCP server listens to this communication and starts talking to the modem. The modem then transmits its MAC address to the DHCP server. At that point, either an IP has been reserved for the modem or one is assigned at that time. Hence cloning your MAC address to get a new IP from your ISP.

Routers and DHCP - Under the General Setup or LAN Setup tab in your router, you'll see a settings option for DHCP. You can control how many IPs are assigned or to enable/disable the DHCP server portion of the router. If you disable it, you'll have to statically assign IPs to each computer, or have a DHCP server or your network. This goes for wired and wireless. Any connection on your network has an IP address.

There's a lot more to DHCP than this, but this is a basic explanation.

- JMD Computer India

Source:- http://www.whatismyip.com/faq/what-is-dhcp.asp

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IP Address Management

What is IP Address Management or IPAM?

By breaking down and assigning your internal IP block into segments allows faster troubleshooting when monitoring the network and seeing an erratic IP. Because you’ve segmented the IPs out, you’ll know exactly which segment it’s coming from and can narrow down finding it faster.

Why manage IPs?

Easily track when network monitor software shows errors. If you’re logged on locally to a User’s computer and you’re mapping batch file didn’t run and you need to get a file from one of your servers you don’t have to know the server name, you can simply type \\192.168.1.x to get access to the server you’re needing the file from.

In the scenario I explain below, we’ll have 1 External IP, 5 servers ((Static) 1 handles DHCP (2k3)), 10 printers (Static), 200 wired PCs/users (DHCP).


There are several different ways to set up exact scenarios. This scenario will explain IP Address Management (IPAM) for a small network using my experience and knowledge.


For ease of use, we’re going to say that this is in a brand new facility where no IPs have been assigned and you, as the LAN Admin, have just been told your internet connection is in place and ready to use (this is where the single external IP comes from).


You already know how many devices will be connected to your network in the beginning so it’s now time to lay out a plan. Since most everyone is familiar with the 192.168.1.x IPs, I’ll stick with those. Technically, your first IP is 192.168.1.0 and your last is 192.168.1.255 which gives you 256 IPs. I don’t know of anyone that uses 192.168.1.0. Since we’re human, the first number to us is 1. To a computer, the first number is 0. I don’t think .255 is useable so really, you have 254 IPs available. Your 5 servers should get your first 5 IP addresses and assign them statically even though you can control static assignment in DHCP. You don’t want there to be any chance of these servers losing their IP addresses so you don’t want them to depend on DHCP for IP assignment.


Server 1 also happens to be your DHCP server: 192.168.1.1
Server 2: 192.168.1.2
Server 3: 192.168.1.3
Server 4: 192.168.1.4
Server 5: 192.168.1.5


You have to account for growth so leave .6 through .9 open for future servers whether they’re physical or virtual, they’ll need an IP.


You have 10 printers that will be used by multiple users. IPs in the next segment of the block can be statically assigned at the printer or via the DHCP server…your choice. Every office has a “main” printer/copier/fax. Give it 192.168.1.10. If you think far enough in advance and know that Group 1 will use printer 1 then assign printer 1 192.168.10.11, printer 2 for Group 2 would get 192.168.10.12, etc. all the way through .19. In my experience, if there’s any one piece of equipment you’ll add to your network more than any other, it’ll be a printer. Somebody in one of those groups will get tired of walking 15 feet to the printer and suck up to the boss to get their own printer. Then, people within 5 feet of that person will want to share with them so they don’t have to walk 15 feet to get their stuff either. So that printer will need to be on the network vs. just connected directly to the complainers PC and shared. Lucky you. By the way, remember at the beginning I said this was a brand new facility….hopefully, the people that ran the network drops put in 2 cables at each requested location. Otherwise, you’ll either need to run a cable or take the easy way out and install a 5 port switch. Trust me when I say leave plenty of IPs open for future printers. I would assign .10 through .29 for printers. This gives you 20 IPs for printers so you’ll have 10 IPs free after installing the initial 10 printers.


Finally, we have 200 PCs that will all be hardwired to the LAN and will each need an IP. Starting at .30 going through and including .254 gives you 225 IPs. I’d start my scope in DHCP at .40 through .254. That gives you 215 IPs for users (15 extra) and that also leaves 10 IPs open at the lower range (.30 through .39) for device growth. One thing I didn’t mention yet was managed switches. They’ll need IPs. You can do those at the high end of the spectrum so they’re “out of the way”. Maybe assign them .254, .253, .252, etc. depending on how many you have.


IPAM can get pretty deep especially if you’re dealing with 100’s of PCs and devices. This is where subnetting comes in. I’ll go into further detail in another article, but just for gee whiz this is the tip of the iceberg on subnetting:


For example, 192.168.1.1 with a subnet of 255.255.255.0 is not on the same network as 192.168.2.1 with a subnet of 255.255.255.0 even though they both might be in the same building. However, if you change the third octet in the subnet to 0 like this 255.255.0.0 now 192.168.1.1 with a subnet of 255.255.0.0 and 192.168.2.1 with a subnet of 255.255.0.0 are on the same network. The 255 is sort of a true/false in simple terms, but can get pretty complex if you’re trying to keep networks separate. I’m not a subnet guru by any means, but if you Google subnet calculator you can get a pretty good appreciation for its complexity.

Source: http://www.whatismyip.com/faq/ip-address-management.asp

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What Is An IP Address?

IP Address (Internet Protocol Address):

This number is an exclusive number all information technology devices (printers, routers, modems, et al) use which identifies and allows them the ability to communicate with each other on a computer network. There is a standard of communication which is called an Internet Protocol standard (IP). In laymans terms it is the same as your home address. In order for you to receive snail mail at home the sending party must have your correct mailing address (IP address) in your town (network) or you do not receive bills, pizza coupons or your tax refund. The same is true for all equipment on the internet. Without this specific address, information cannot be received. IP addresses may either be assigned permanently for an Email server/Business server or a permanent home resident or temporarily, from a pool of available addresses (first come first serve) from your Internet Service Provider. A permanent number may not be available in all areas and may cost extra so be sure to ask your ISP.

Domain Name System (DNS): This allows the IP address to be translated to words. It is much easier for us to remember a word than a series of numbers. The same is true for email addresses.

For example, it is much easier for you to remember a web address name such as whatismyip.com than it is to remember 192.168.1.1 or in the case of email it is much easier to remember email@somedomain.com than email@192.168.1.1

Dynamic IP Address: An IP address that is not static and could change at any time. This IP address is issued to you from a pool of IP addresses allocated by your ISP or DHCP Server. This is for a large number of customers that do not require the same IP Address all the time for a variety of reasons. Your computer will automatically get this number as it logs on to the network and saves you the trouble of having to know details regarding the specific network configurations. This number can be assigned to anyone using a dial-up connection, Wireless and High Speed Internet connections. If you need to run your own email server or web server, it would be best to have a static IP.

Static IP Address: An IP address that is fixed and never changes. This is in contrast to a dynamic IP address which may change at any time. Most ISP's a single static IP or a block of static IP's for a few extra bucks a month.

IP version 4: Currently used by most network devices. However, with more and more computers accessing the internet, IPv4 addresses are running out quickly. Just like in a city, addresses have to be created for new neighborhoods but, if your neighborhood gets too large, you will have to come up with an entire new pool of addresses. IPv4 is limited to 4,294,967,296 addresses.

IP version 5: This is an experimental protocol for UNIX based systems. In keeping with standard UNIX (a computer Operating System) release conventions, all odd-numbered versions are considered experimental. It was never intended to be used by the general public.

IP version 6: The replacement for the aging IPv4. The estimated number of unique addresses for IPv6 is 340,282,366,920,938,463,463,374,607,431,768,211,456 or 2^128.

The old and current standard of addresses was this: 192.168.100.100 the new way can be written different ways but means the same and are all valid:

* 1080:0000:0000:0000:0000:0034:0000:417A

* 1080:0:0:0:0:34:0:417A

* 1080::34:0:417A

Source: http://www.whatismyip.com/faq/what-is-an-ip-address.asp

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