BeamOS – Routes
Summary
ARP
The Address Resolution Protocol (ARP) is a communication protocol used for mapping an Internet Protocol address (IP address) to a physical machine’s link layer address (MAC address) belonging to the local network.
The ARP section displays the router’s ARP cache (also known as ARP table) data. The ARP cache contains information on each known MAC address and its corresponding IP address. When the router receives a packet destined for a local host, the ARP program attempts to find a physical host or MAC address in the ARP cache that matches the IP address. If the ARP cache doesn’t contain the needed IP address, ARP broadcasts a request packet to all LAN machines in order to find the device with the IP address in question.
The figure below is an example of the ARP cache section:
Field Name | Value | Description |
|---|---|---|
IP Address | ip; Default: none | IP address of a local host |
MAC Address | mac; Default: none | MAC address of a local host |
Interface | string; Default: none | Interface through which the router is associated with the host |
root@beam-onboard:~# arp IP address HW type Flags HW address Mask Device
192.168.1.103 0x1 0x2 ac:e2:d3:00:00:00 * br-lan
192.168.1.151 0x1 0x2 18:d6:c7:00:00:00 * br-lanroot@beam-onboard:~# ip neigh
192.168.1.103 dev br-lan lladdr ac:e2:d3:00:00:00 REACHABLE
192.168.1.151 dev br-lan lladdr 18:d6:c7:00:00:00 REACHABLE
Active IP routes
The Active IP routes section displays the router’s routing table. A routing table contains a list of routes to network destinations associated with and known by the router.
The figure below is an example of the Active IP routes section:
Field Name | Value | Description |
|---|---|---|
Network | string; Default: none | Associated network interface name |
Target | ip | ip/netmask; Default: none | Destination network address |
IP Gateway | ip; Default: none | Indicates the IP address of the gateway through which the target network can be reached |
Metric | integer [0..4,294,967,295]; Default: none | Metrics help the router choose the best route among multiple feasible routes to a destination. The route will go in the direction of the gateway with the lowest metric value |
root@beam-onboard:~# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default 10.1.179.213 0.0.0.0 UG 0 0 0 wwan0
10.1.179.208 * 255.255.255.248 U 10 0 0 wwan0
10.1.179.213 * 255.255.255.255 UH 10 0 0 wwan0
192.168.1.0 * 255.255.255.0 U 0 0 0 br-lanroot@beam-onboard:~# ip route
default via 10.1.179.213 dev wwan0
10.1.179.208/29 dev wwan0 proto static scope link metric 10
10.1.179.213 dev wwan0 proto static scope link src 10.1.179.212 metric 10
192.168.1.0/24 dev br-lan proto kernel scope link src 192.168.1.1 Active IPv6 routes
The Active IPv6 routes section displays the router’s IPv6 routing table.
The figure below is an example of the Active IPv6 routes section:
Field Name | Value | Description |
|---|---|---|
Network | string; Default: none | Associated network interface name |
Target | ip | ip/netmask; Default: none | Destination network address |
IP Gateway | ip; Default: none | Indicates the IPv6 address of the gateway through which the target network can be reached |
Metric | integer [0..4,294,967,295]; Default: none | Metrics help the router choose the best route among multiple feasible routes to a destination. The route will go in the direction of the gateway with the lowest metric value |
root@beam-onboard:~# ip -6 route fe80::/64 dev wwan0 proto kernel metric 256