Monitoring

VyOS features several monitoring tools.

vyos@vyos:~$ monitor
Possible completions:
  bandwidth     Monitor interface bandwidth in real time
  bandwidth-test
                Initiate or wait for bandwidth test
  cluster       Monitor clustering service
  command       Monitor an operational mode command (refreshes every 2 seconds)
  conntrack-sync
                Monitor conntrack-sync
  content-inspection
                Monitor Content-Inspection
  dhcp          Monitor Dynamic Host Control Protocol (DHCP)
  dns           Monitor a Domain Name Service (DNS) daemon
  firewall      Monitor Firewall
  https         Monitor the Secure Hypertext Transfer Protocol (HTTPS) service
  lldp          Monitor Link Layer Discovery Protocol (LLDP) daemon
  log           Monitor last lines of messages file
  nat           Monitor network address translation (NAT)
  ndp           Monitor the NDP information received by the router through the device
  openvpn       Monitor OpenVPN
  protocol      Monitor routing protocols
  snmp          Monitor Simple Network Management Protocol (SNMP) daemon
  stop-all      Stop all current background monitoring processes
  traceroute    Monitor the path to a destination in realtime
  traffic       Monitor traffic dumps
  vpn           Monitor VPN
  vrrp          Monitor Virtual Router Redundancy Protocol (VRRP)
  webproxy      Monitor Webproxy service

Traffic Dumps

To monitor interface traffic, issue the monitor traffic interface <name> command, replacing <name> with your chosen interface.

vyos@vyos:~$ monitor traffic interface eth0
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
15:54:28.581601 IP 192.168.0.1 > vyos: ICMP echo request, id 1870, seq 3848, length 64
15:54:28.581660 IP vyos > 192.168.0.1: ICMP echo reply, id 1870, seq 3848, length 64
15:54:29.583399 IP 192.168.0.1 > vyos: ICMP echo request, id 1870, seq 3849, length 64
15:54:29.583454 IP vyos > 192.168.0.1: ICMP echo reply, id 1870, seq 3849, length 64
^C
4 packets captured
4 packets received by filter
0 packets dropped by kernel
vyos@vyos:~$

To quit monitoring, press Ctrl-C and you’ll be returned to the VyOS command prompt.

Traffic can be filtered and saved.

vyos@vyos:~$ monitor traffic interface eth0
Possible completions:
  <Enter>       Execute the current command
  filter        Monitor traffic matching filter conditions
  save          Save traffic dump from an interface to a file

Interface Bandwidth Usage

To quickly view the bandwidth usage of an interface, use the monitor bandwidth command:

vyos@vyos:~$ monitor bandwidth interface eth0

This shows the following:

     B                      (RX Bytes/second)
00 .|....|.....................................................
00 .|....|.....................................................
00 ||..|.|.....................................................
00 ||..|.|.....................................................
00 |||||||.....................................................
00 |||||||.....................................................
       1   5   10   15   20   25   30   35   40   45   50   55   60

   KiB                      (TX Bytes/second)
67 ......|.....................................................
06 ......|.....................................................
45 ......|.....................................................
84 ......|.....................................................
22 ......|.....................................................
61 :::::||.....................................................
       1   5   10   15   20   25   30   35   40   45   50   55   60

Interface Performance

To take a look on the network bandwidth between two nodes, the monitor bandwidth-test command is used to run iperf.

vyos@vyos:~$ monitor bandwidth-test
Possible completions:
  accept        Wait for bandwidth test connections (port TCP/5001)
  initiate      Initiate a bandwidth test

The accept command opens a listening iperf server on TCP Port 5001
The initiate command connects to that server to perform the test.

vyos@vyos:~$ monitor bandwidth-test initiate
Possible completions:
  <hostname>    Initiate a bandwidth test to specified host (port TCP/5001)
  <x.x.x.x>
  <h:h:h:h:h:h:h:h>

Monitor command

The monitor command command allows you to repeatedly run a command to view a continuously refreshed output. The command is run and output every 2 seconds, allowing you to monitor the output continuously without having to re-run the command. This can be useful to follow routing adjacency formation.

vyos@router:~$ monitor command "show interfaces"

Will clear the screen and show you the output of show interfaces every 2 seconds.

Every 2.0s: /opt/vyatta/bin/vyatta-op-cmd-wrapper    Sun Mar 26 02:49:46 2019

Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface        IP Address                        S/L  Description
---------        ----------                        ---  -----------
eth0             192.168.1.1/24                    u/u
eth0.5           198.51.100.4/24                   u/u  WAN
lo               127.0.0.1/8                       u/u
                 ::1/128
vti0             172.25.254.2/30                   u/u
vti1             172.25.254.9/30                   u/u