.. _troubleshooting: Troubleshooting =============== Sometimes things break or don't work as expected. This section describes several troubleshooting tools provided by VyOS that can help when something goes wrong. Basic Connectivity Verification ------------------------------- Verifying connectivity can be done with the familiar `ping` and `traceroute` commands. The options for each are shown (the options for each command were displayed using the built-in help as described in the :ref:`cli` section and are omitted from the output here): .. code-block:: none vyos@vyos:~$ ping Possible completions: Send Internet Control Message Protocol (ICMP) echo request Several options are available when more extensive troubleshooting is needed: .. code-block:: none vyos@vyos:~$ ping 10.1.1.1 Possible completions: Execute the current command adaptive Ping options allow-broadcast audible bypass-route count deadline flood interface interval mark no-loopback numeric pattern quiet record-route size timestamp tos ttl verbose .. code-block:: none vyos@vyos:~$ traceroute Possible completions: Track network path to specified node ipv4 Track network path to ipv6 Track network path to However, another tool, mtr_, is available which combines ping and traceroute into a single tool. An example of its output is shown: .. code-block:: none vyos@vyos:~$ mtr 10.62.212.12 My traceroute [v0.85] vyos (0.0.0.0) Keys: Help Display mode Restart statistics Order of fields quit Packets Pings Host Loss% Snt Last Avg Best Wrst StDev 1. 10.11.110.4 0.0% 34 0.5 0.5 0.4 0.8 0.1 2. 10.62.255.184 0.0% 34 1.1 1.0 0.9 1.4 0.1 3. 10.62.255.71 0.0% 34 1.4 1.4 1.3 2.0 0.1 4. 10.62.212.12 0.0% 34 1.6 1.6 1.6 1.7 0.0 .. note:: The output of ``mtr`` consumes the screen and will replace your command prompt. Several options are available for changing the display output. Press `h` to invoke the built in help system. To quit, just press `q` and you'll be returned to the VyOS command prompt. Monitoring ---------- VyOS features several monitoring tools. .. code-block:: none 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 Monitors 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 :code:`monitor traffic interface ` command, replacing `` with your chosen interface. .. code-block:: none 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. .. code-block:: none vyos@vyos:~$ monitor traffic interface eth0 Possible completions: Execute the current command filter Monitor traffic matching filter conditions save Save traffic dump from an interface to a file Interface Bandwidth ^^^^^^^^^^^^^^^^^^^ to take a quick view on the used bandwidth of an interface use the ``monitor bandwidth`` command .. code-block:: none vyos@vyos:~$ monitor bandwidth interface eth0 show the following: .. code-block:: none B (RX Bytes/second) 198.00 .|....|..................................................... 165.00 .|....|..................................................... 132.00 ||..|.|..................................................... 99.00 ||..|.|..................................................... 66.00 |||||||..................................................... 33.00 |||||||..................................................... 1 5 10 15 20 25 30 35 40 45 50 55 60 KiB (TX Bytes/second) 3.67 ......|..................................................... 3.06 ......|..................................................... 2.45 ......|..................................................... 1.84 ......|..................................................... 1.22 ......|..................................................... 0.61 :::::||..................................................... 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. .. code-block:: none 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. .. code-block:: none vyos@vyos:~$ monitor bandwidth-test initiate Possible completions: Initiate a bandwidth test to specified host (port TCP/5001) 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. .. code-block:: none vyos@router:~$ monitor command "show interfaces" Will clear the screen and show you the output of ``show interfaces`` every 2 seconds. .. code-block:: none 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 Clear Command ------------- Sometimes you need to clear counters or statistics to troubleshoot better. To do this use the ``clear`` command in Operational mode. to clear the console output .. code-block:: none vyos@vyos:~$ clear console to clear interface counters .. code-block:: none # clear all interfaces vyos@vyos:~$ clear interface ethernet counters # clear specific interface vyos@vyos:~$ clear interface ehternet eth0 counters The command follow the same logic as the ``set`` command in configuration mode. .. code-block:: none # clear all counters of a interface type vyos@vyos:~$ clear interface counters # clear counter of a interface in interface_type vyos@vyos:~$ clear interface counters to clear counters on firewall rulesets or single rules .. code-block:: none vyos@vyos:~$ clear firewall name counters vyos@vyos:~$ clear firewall name rule counters vyos@vyos:~$ clear firewall ipv6-name counters vyos@vyos:~$ clear firewall ipv6-name rule counters IPv6 topology discovery ----------------------- Topology discovery tool supporting IPv6 in vyos1.3 Router discovery ^^^^^^^^^^^^^^^^ Vyos 1.3 supports the following commands to complete IPv6 Router Discovery: .. code-block:: none vyos@vyos:~$ force ipv6-rd interface [address ] Example: .. code-block:: none vyos@vyos:~$ force ipv6-rd interface eth0 Soliciting ff02::2 (ff02::2) on eth0... Hop limit : 60 ( 0x3c) Stateful address conf. : No Stateful other conf. : No Mobile home agent : No Router preference : high Neighbor discovery proxy : No Router lifetime : 1800 (0x00000708) seconds Reachable time : unspecified (0x00000000) Retransmit time : unspecified (0x00000000) Prefix : 240e:fe:8ca7:ea01::/64 On-link : Yes Autonomous address conf.: Yes Valid time : 2592000 (0x00278d00) seconds Pref. time : 14400 (0x00003840) seconds Prefix : fc00:470:f1cd:101::/64 On-link : Yes Autonomous address conf.: Yes Valid time : 2592000 (0x00278d00) seconds Pref. time : 14400 (0x00003840) seconds Recursive DNS server : fc00:470:f1cd::ff00 DNS server lifetime : 600 (0x00000258) seconds Source link-layer address: 00:98:2B:F8:3F:11 from fe80::298:2bff:fef8:3f11 Neighbor Discovery ^^^^^^^^^^^^^^^^^^ Vyos1.3 supports IPv6 host topology detection. The following commands can be used to detect the occupation of IPv6 address: .. code-block:: none vyos@vyos:~$ force ipv6-nd interface address Example: .. code-block:: none vyos@vyos:~$ force ipv6-nd interface eth0 address fc00:470:f1cd:101::1 Soliciting fc00:470:f1cd:101::1 (fc00:470:f1cd:101::1) on eth0... Target link-layer address: 00:98:2B:F8:3F:11 from fc00:470:f1cd:101::1 Basic System Information ------------------------ Boot steps ^^^^^^^^^^ VyOS 1.2 uses `Debian Jessie`_ as the base Linux operating system. Jessie was the first version of Debian that uses systemd_ as the default init system. These are the boot steps for VyOS 1.2 1. The BIOS loads Grub (or isolinux for the Live CD) 2. Grub then starts the Linux boot and loads the Linux Kernel ``/boot/vmlinuz`` 3. Kernel Launches Systemd ``/lib/systemd/systemd`` 4. Systemd loads the VyOS service file ``/lib/systemd/system/vyos-router.service`` 5. The service file launches the VyOS router init script ``/usr/libexec/vyos/init/vyos-router`` - this is part of the vyatta-cfg_ Debian package 1. Starts FRR_ - successor to `GNU Zebra`_ and Quagga_ 2. Initialises the boot configuration file - copies over ``config.boot.default`` if there is no configuration 3. Runs the configuration migration, if the configuration is for an older version of VyOS 4. Runs The pre-config script, if there is one ``/config/scripts/vyos-preconfig-bootup.script`` 5. If the config file was upgraded, runs any post upgrade scripts ``/config/scripts/post-upgrade.d`` 6. Starts ``rl-system`` and ``firewall`` 7. Mounts the ``/boot`` partition 8. The boot configuration file is then applied by ``/opt/vyatta/sbin/ vyatta-boot-config-loader/opt/vyatta/etc/config/config.boot`` 1. The config loader script writes log entries to ``/var/log/vyatta-config-loader.log`` 10. Runs ``telinit q`` to tell the init system to reload ``/etc/inittab`` 11. Finally it runs the post-config script ``/config/scripts/vyos-postconfig-bootup.script`` .. _Quagga: https://www.quagga.net/ .. _`GNU Zebra`: https://www.gnu.org/software/zebra/ .. _FRR: https://frrouting.org/ .. _vyatta-cfg: https://github.com/vyos/vyatta-cfg .. _systemd: https://freedesktop.org/wiki/Software/systemd/ .. _`Debian Jessie`: https://www.debian.org/releases/jessie/ .. _mtr: http://www.bitwizard.nl/mtr/ .. _tshark: https://www.wireshark.org/docs/man-pages/tshark.html .. _`PCAP filter expressions`: http://www.tcpdump.org/manpages/pcap-filter.7.html