What is the minimum Ethernet frame size that will not be discarded by the receiver as a runt frame?
The Ethernet frame which has a size of fewer than 64 bytes will be discarded as a runt frame by the receiver. So that we can say that the Ethernet frame’s lowest or the Ethernet frame’s minimal size is 64 bytes. We can also say that an Ethernet frame that has a size of fewer than 64 bytes will be considered as collision fragments. So, if the receiver is receiving such type of an Ethernet frame, it will be discarded.
Likewise, there is also a maximum limit in the size of an Ethernet frame which is 1518 bytes in size. So the Ethernet frame cannot exceed its size larger than 1518 bytes to avoid the discarding of the frame by the receiver as runt frames or jumbo frames collision fragments.
The minimum and the maximum Ethernet frame size is defined in the Ethernet IEEE 802.3 standard. And these minimum and maximum sizes are 64 and 1518 respectively. Later, the maximum frame size has increased from 1518 to 1522. This is done for allowing the VLAN tagging.
Therefore, to care about or to avoid the frame runt and jump frames, the network technician should know about the maximum and the minimum size of the Ethernet frames.
The minimum frame size is 64 and these 64 bytes has been portioned into,
- Destination address(6)
- Frame type(2)
- Source address(6)
- CRC checksum(4)
If an Ethernet frame is carrying an ICMP packet, then the minimum size of that Ethernet frame will be 74 in size. We can test this in the following way. This is with the help of a packet analyzer. It can be done just by installing the packet analyzer on our system. And then, a ping packet with no option is run into the destination. Where the destination is inside in the same sender’s network.
- Introduction to Network Protocol Analyzer (Sniffers)
- Leading Network Protocol Analyzer (Sniffer) Products
- What is Firewall and its types -Hardware firewall, Software Firewall
- What is Ping Spoofing
This process will create a packet with a size of 74 bytes. Where in these 64 bytes, the 60 bytes will be the IP header, 8 bytes will be the ICMP header and the remaining will be the Ethernet frame size. If we want to add extra length for the packet, then the maximum size can be specified by adjusting the options present in the ICMP payload. The MTU present in the Ethernet LAN limits all these and by default, it would 1500 bytes in length.
I hope you understood the explanation given by me for minimum Ethernet frame size that will not be discarded by the receiver as a runt frame.