TCP/IP Tools Assistant

This application is also equipped with what I believe to be some handy extra’s that should prove invaluable to network administrators. Three tools as stated below are provided. Please click on either of them for more details:

1) Binary/Decimal/Hex Conversion Tool

2) Non Canonical/Canonical MAC Address Converter

3) Vendor Code MAC Address Assistant

4) Common TCP/UDP Port Numbers

5) Common TCP/IP Multicast Addresses

Binary/Decimal/Hex Conversion Tool

In any situation where you are working with TCP/IP addresses and subnetting, binary conversion is almost a must. This program comes with a binary to decimal to hex calculator to assist you in your calculations.

This function is limited to inputting either

- A binary number up to 8 digits in length, OR
- A decimal number in the range of 0 to 255, OR
- A hexadecimal number in the range 0 to FF

The decimal range is there because in TCP/IP you will always work with numbers in that range (Each TCP/IP address byte is only 8 bits in length).

To use the converter, enter a number in either field and either press the calculate button or just hit the "ENTER" button.

Non Canonical/Canonical MAC Address Converter

Token Ring and Ethernet both use a MAC (Media Access Control) number that is assigned to the NIC (Network Interface Card) by the manufacturer. This is called the UAA (or Universal Administered Address). This address can be overridden by the network administrator. The MAC address assigned by an administrator is called a LAA (or Locally Administered Address).

The MAC address is a 48 bit address (6 bytes).

Token Ring and Ethernet interpret the MAC address in a different way. Token Ring will read the MAC address from the high order bit of each byte to the lowest order bit. Ethernet reads the bits of each byte from the lowest order bit to the high order bit.

As an example, take the following token ring LAA MAC address

4000 0C0C 0101

The MAC address is broken up into each byte as follows

40 00 0C 0C 01 01

(40) (00) (0C) (0C) (01) (01)

convert it to binary (brackets are used to group each byte together:

(0100 0000) (0000 0000) (0000 1100) (0000 1100) (0000 0001) (0000 0001)

To convert to ethernet, take each byte and read it in reverse, e.g.

(0000 0010) (0000 0000) (0011 0000) (0011 0000) (1000 0000) (1000 0000)

This results in the MAC address being read as:

(02) (00) (30) (30) (80) (80)

Thus a Token Ring MAC address of 4000 0C0C 0101 is read as

0200 3030 8080.

REMEMBER : Token Ring MAC addresses are always referred to as NON Canonical, ..Ethernet MAC addresses are referred to as Canonical.

Vendor Code MAC Address Assistant

Each MAC address has a built in vendor code. The first six digits of the MAC address are pre-assigned to a vendor. It represents a unique identifier for that vendor.

This facility to display the vendor codes and their respective owners ethernet MAC address. If you only have the token ring MAC address, use the Canonical <-> Non-canonical conversion facility to convert the MAC address to Ethernet.

N.B. This facility displays the Vendor Codes in Canonical format (Ethernet format).

Common TCP/UDP Port Numbers

Both TCP and UDP use port numbers to indicate the type of traffic they are handling to the upper layers of the OSI stack. This facility in this program displays some of the more common reserved port numbers used by TCP and UDP. Most of the port numbers are common to both TCP and UDP. Those ports unique to either TCP or UDP are indicated in the list.

Some of the more common port numbers referenced are :

- 21 FTP
- 23 Telnet
- 25 SMTP
- 53 DNS
- 67/68 BOOTP
- 69 TFTP
- 161 SNMP

For more information on TCP/UDP port numbers, please refer to RFC 1700.

Common TCP/IP Multicast Addresses

TCP/IP uses multicast addresses to send data to a select group of hosts. Some of the more common multicast addresses are displayed using this program.

Last Modified 12 August 1996 - Carl Solder