diff --git a/05. Ethernet LAN Switching.md b/05. Ethernet LAN Switching (part 1).md similarity index 99% rename from 05. Ethernet LAN Switching.md rename to 05. Ethernet LAN Switching (part 1).md index 2165160..92c0fa6 100644 --- a/05. Ethernet LAN Switching.md +++ b/05. Ethernet LAN Switching (part 1).md @@ -5,7 +5,7 @@ aliases: tags: [] --- -# Ethernet LAN Switching +# Ethernet LAN Switching (part 1) ## [[OSI model]] - physical layer diff --git a/06. Ethernet LAN Switching (part 2).md b/06. Ethernet LAN Switching (part 2).md new file mode 100644 index 0000000..c6748d1 --- /dev/null +++ b/06. Ethernet LAN Switching (part 2).md @@ -0,0 +1,91 @@ +--- +id: 06. Ethernet LAN Switching (part 2) +aliases: [] +tags: [] +--- + +# Ethernet LAN Switching (part 2) + +## Ethernet Frame + +- The preamble + SFD is usually not considered part of the Ethernet header +- therefore the size of the Ethernet header + trailer is 18 bytes (6+6+2+4) +- the minimum size for an Ethernet frame (Header + payload (Packet) + trailer) is 64 [[bytes]] +- 64 bytes - 18 bytes (header + trailer size) = 46 bytes +- therefore the minimum payload (packet) size is 46 bytes +- if the payload is less than 46 bytes, padding bytes are added +- ie. 34-byte packet + 12-byte padding = 46 bytes + +## [[ARP]] + +- ARP stands for 'Address Resolution Protocol' +- ARP is used to discover the Layer 2 address [[Mac address]] of a known Layer 3 address [[IP address]] +- Consists of two messages: + - ARP Request + - ARP Request is broadcast = sent to all hosts on the network + - ARP Reply + - ARP REply is unicast = sent only to one host (the host that sent the request) + +## ARP Table + +- command to view the ARP table + - use *[[arp]] -a* ([[Windows]], [[macOS]], [[Linux]]) + - use *show arp* ([[Cisco]] devices) +- Internet Address = IP address (layer 3 address) +- Physical Address = MAC address (layer 2 address) +- type static = default entry +- type dynamic = learned via ARP + +## [[Ping]] + +- A network utility that is used to test reachability +- Measures round-trip time +- Uses two messages + - [[ICMP]] Echo Request + - [[ICMP]] Echo Reply +- command to use pin: *ping (ip-address)* + +## MAC address table + +command to view it + - *show mac address-table* + + +```cisco +SW1#show mac address table + +Vlan Mac Address Type Ports +---- ----------- ---- ----- + 1 0c2f.b011.9d00 DYNAMIC Gi0/0 + 1 0c2f.b06a.3900 DYNAMIC Gi0/2 + +Total Mac addresses for this criterion: 2 +``` + +- [[Vlan]] : Virtual local area network +- Ports = Interface + +## Clearing the Mac address Table + +for manually remove mac address table use this command + - *clear mac address-table dynamic* +for just one mac address + - *clear mac address-table dynamic address (mac address)* + - *clear mac address-table dynamic address 0c2f.b06a.3900* +for one interface + - *clear mac address-table dynamic interface (interface)* + - *clear mac address-table dynamic interface Gi0/0* + +## Summary +- Ethernet frame payload minimum size +- ARP (Address Resolution Protocol) + - ARP Request + - ARP Reply +- ARP table +- Ping + - ICMP Echo Request + - ICMP Echo Reply +- Mac Address Table + + +