Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: ????

---------------

IPv4

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: ????

---------------

IPv4

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: ff:ff:ff:ff:ff

---------------

Arp Request for 10.40.8.1​

H1 sends an ARP request to find the MAC of the router (he already knows its IP)

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: ????

---------------

IPv4

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: ff:ff:ff:ff:ff

---------------

Arp Request for 10.40.8.1​

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)
  • The router responds to the ARP Request with an ARP reply

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: ????

---------------

IPv4

Etherne:

MAC Src: 2c:f8:9b:34:e1:be

MAC Dst: f0:b6:1e:bb:1a:3e

---------------

Arp reply 10.40.8.1 is at 2c:f8:9b:34:e1:be

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)
  • The router responds to the ARP Request with an ARP reply

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: ????

---------------

IPv4

Etherne:

MAC Src: 2c:f8:9b:34:e1:be

MAC Dst: f0:b6:1e:bb:1a:3e

---------------

Arp reply 10.40.8.1 is at 2c:f8:9b:34:e1:be

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)
  • The router responds to the ARP Request with an ARP reply

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: 2c:f8:9b:34:e1:be

---------------

IPv4

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)
  • The router responds to the ARP Request with an ARP reply
  • Now the router doesn't know the MAC of the next Hop
    12.14.6.20 (H2) which is connected on Port 1.

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: 2c:f8:9b:34:e1:be

---------------

IPv4

Etherne:

MAC Src: 2c:f8:9b:34:e1:be​

MAC Dst: ff:ff:ff:ff:ff

---------------

Arp Request for 12.14.6.20​

The router sends an ARP Request

The Packet is in queue because we want to be able to receive other packets in the meantime

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)
  • The router responds to the ARP Request with an ARP reply
  • Now the router doesn't know the MAC of the next Hop
    12.14.6.20 (H2) which is connected on Port 1.

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: 2c:f8:9b:34:e1:be

---------------

IPv4

Etherne:

MAC Src: 2c:f8:9b:34:e1:be​

MAC Dst: ff:ff:ff:ff:ff

---------------

Arp Request for 12.14.6.20​

The Packet is in queue because we want to be able to receive other packets in the meantime

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)
  • The router responds to the ARP Request with an ARP reply
  • Now the router doesn't know the MAC of the next Hop
    12.14.6.20 (H2) which is connected on Port 1.

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: 2c:f8:9b:34:e1:be

---------------

IPv4

Etherne:

MAC Src: 2c:f8:9b:34:e1:be​

MAC Dst: ff:ff:ff:ff:ff

---------------

Arp Request for 12.14.6.20​

Etherne:

MAC Src: a0:36:5d:1b:6a:ee​

MAC Dst: 2c:f8:9b:34:e1:be​

---------------

Arp Reply  12.14.6.20​ is at a0:36:5d:1b:6a:ee​

The Packet is in queue because we want to be able to receive other packets in the meantime

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC
12.14.6.20 a0:36:5d:1b:6a:ee​

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)
  • The router responds to the ARP Request with an ARP reply
  • Now the router doesn't know the MAC of the next Hop
    12.14.6.20 (H2) which is connected on Port 1.
  • The router updated the ARP cache table with the info from the reply

Etherne:

MAC Src: f0:b6:1e:bb:1a:3e

MAC Dst: 2c:f8:9b:34:e1:be

---------------

IPv4

Etherne:

MAC Src: a0:36:5d:1b:6a:ee​

MAC Dst: 2c:f8:9b:34:e1:be​

---------------

Arp Reply  12.14.6.20​ is at a0:36:5d:1b:6a:ee​

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC
12.14.6.20 a0:36:5d:1b:6a:ee​

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)
  • The router responds to the ARP Request with an ARP reply
  • Now the router doesn't know the MAC of the next Hop
    12.14.6.20 (H2) which is connected on Port 1.
  • The router updated the ARP cache table with the info from the reply

Etherne:

MAC Src: 2c:f8:9b:34:e1:be​

MAC Dst: a0:36:5d:1b:6a:ee​

---------------

IPv4

Router 1

IP:10.40.8.29

MAC:f0:b6:1e:bb:1a:3e

IP:12.14.6.20​

MAC:a0:36:5d:1b:6a:ee​

Port: 0​

IP: 10.40.8.1​

Port: 1​

IP: 12.14.6.1​

MAC: 2c:f8:9b:34:e1:be​

H1

IP MAC
12.14.6.20 a0:36:5d:1b:6a:ee​

Tabela cache ARP

H1

H2

  • Initially no one know anyone's MAC
  • H1 wants to send an IPv4 packet to H2, but doesn't know
    the Router's MAC (directly connected over the Link)
  • The router responds to the ARP Request with an ARP reply
  • Now the router doesn't know the MAC of the next Hop
    12.14.6.20 (H2) which is connected on Port 1.
  • The router updated the ARP cache table with the info from the reply

Etherne:

MAC Src: 2c:f8:9b:34:e1:be​

MAC Dst: a0:36:5d:1b:6a:ee​

---------------

IPv4