Connectivity Tests

Basic Connectivity Tests

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 Command Line Interface section and are omitted from the output here):

ping <destination>

Send ICMP echo requests to destination host. There are multiple options to ping, including VRF support.

vyos@vyos:~$ ping 10.1.1.1
Possible completions:
  <Enter>       Execute the current command
  adaptive      Ping options
  allow-broadcast
  audible
  bypass-route
  count
  deadline
  do-not-fragment
  flood
  interface
  interval
  mark
  no-loopback
  numeric
  pattern
  quiet
  record-route
  size
  timestamp
  tos
  ttl
  verbose
  vrf

traceroute <destination>

Trace path to target.

vyos@vyos:~$ traceroute
Possible completions:
  <hostname>    Track network path to specified node
  <x.x.x.x>
  <h:h:h:h:h:h:h:h>
  ipv4          Track network path to <hostname|IPv4 address>
  ipv6          Track network path to <hostname|IPv6 address>

Advanced Connectivity Tests

monitor traceroute <destination>

However, another helper is available which combines ping and traceroute into a single tool. An example of its output is shown:

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 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.

IPv6 Topology Discovery

IPv6 uses different techniques to discover its Neighbors/topology.

Router Discovery

force ipv6-rd interface <interface> [address <ipv6-address>]

Discover routers via eth0.

Example:

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

force ipv6-nd interface <interface> address <ipv6-address>

Example:

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