Today we will see the different Ethernet frame types and there header size.
1)Ethernet encapsulation 802.3
2)Ethernet encapsulation 802.1q Frame
3)Ethernet encapsulation 802.1ad
4)Ethernet encapsulation 802.1ah
Learn to Know Now or Never
Today we will see the different Ethernet frame types and there header size.
1)Ethernet encapsulation 802.3
2)Ethernet encapsulation 802.1q Frame
3)Ethernet encapsulation 802.1ad
4)Ethernet encapsulation 802.1ah
We are having different techlogy when it comes to secure the private network over internet for securely sharing your data in public domain.The figure above depicts the types of VPN services that we can use as per our requirement.We will see each VPN and their features with configuration ahead.
The header fields are discussed below:
IPV4 header is flexible in size and can vary from 20 bytes to 60 bytes. Usually it is 20 bytes in length.
Te Internet Protocol (IP) is defined in RFC 791. The RFC specifies the format of the IP header. In the header there is the IHL (Internet Header Length) field which is 4 bits long and specifies the header length in 32 bit words. The IHL field can hold values from 0 (Binary 0000) to 15 (Binary 1111).
So the longest Internet Header (IP header) size can be 15*32 Bits = 480 Bits = 60 Bytes. This is why the header has a maximum size of 60 Bytes.
The shortest header size is 20 bytes, where the IHL field has the value 5 (0101). This is because all the required fields in the header need 20 Bytes of space. So while in theory you could set the IHL to a value < 5 this would always be an incorrect value and thus an invalid packet header.
Total field in IPv4 is 13 and you can remember these by using the phrase as below.
VIT TIF FTP HSDO
V | I | T | T | I | F | F | T | P | H | S | D | O | |||
ver | IHL | TOS | TL | Indentifier | Flag | Fragment | TTL | Protocol | Checksum | SIP | DIP | Option |