Configuration basics
Terminology
Several versions of system configuration information exist on the system at a given time.
Active or “running” configuration
This configuration is the one that is loaded and being used by the system.
Candidate configuration
When you enter configuration mode and make configuration changes, changes remain in candidate configuration until you commit the changes, at which time the configuration becomes active or running.
Configuration hierarchy
DANOS vRouter configuration is organized as a hierarchy of configuration statements, with a hierarchical tree of nodes similar to the directory structure on a UNIX file system. Three kinds of statements exist:
Configuration nodes. These nodes can be either
Single-nodes (just one instance can be created; for example, the
service ssh timeout)Multi-nodes (more than one instance can be created; for example,
service ssh port)
Attribute statements. These statements set the values or characteristics for parameters within a node.
Navigating in configuration mode
You can tell where you are in the configuration tree by the [edit] prompt, which is context sensitive.
At the top of the configuration tree, the [edit] prompt looks like this:[edit]
When you are in another location, the edit prompt indicates your location by showing the node hierarchy in order, like this:[edit service ssh]
The following commands for navigating in configuration mode are available:
edit config-node
Navigates to the specified configuration node for editing.
The node must already be created the configuration committed.
exit
Jumps to the top of the configuration tree.
If you are already at the top of the configuration tree, exit from configuration mode and return to operational mode.
top
Jumps to the top of the configuration tree.
up
Moves up one node in the configuration tree.
Viewing configuration in configuration mode
Use the show command in configuration mode to display configuration. You can restrict the display to a particular node by specifying the path to the node.
The following example shows how to display configuration for all configured interfaces.
vyatta@R1# show interfaces
interfaces {
dataplane dp0p1s1 {
address 10.10.1.1/24
mac 00:13:46:e6:f6:87
}
dataplane dp0s2 {
address dhcp
}
loopback lo
}
The following example shows how to display configuration for only the dp0p1s1 dataplane interface.
vyatta@R1# show interfaces dataplane dp0p1s1
dataplane dp0p1s1 {
address 10.10.1.1/24
mac 00:13:46:e6:f6:87
}
When the display is too large for one screen, the display stops after one screen is shown. In this case, press one of the following keys to perform the indicated action.
<Enter> to display the next line
<Space> to display the next screen
<q> to interrupt the display and return to the command prompt
Viewing configuration in operational mode
You can display configuration information without leaving operational mode by using the show configuration command, as in the following example.
vyatta@R1:~$ show configuration
interfaces {
dataplane dp0p1s1 {
address 10.10.1.1/24
hw-id 00:13:46:e6:f6:87
}
dataplane dp0s2 {
address dhcp
}
loopback lo
}
service {
netconf
ssh {
port 22
port 830
}
telnet
}
Changing configuration information
Adding or modifying the configuration
Add new configuration by creating a configuration node by using the set command in configuration mode. Modify existing configuration by using the set command in configuration mode, as in the following example.
vyatta@R1# set interfaces dataplane dp0p1s1 address 192.168.1.100/24 vyatta@R1#
Then use the show command to see the change.
vyatta@R1# show interfaces dataplane dp0p1s1 +address 192.168.1.100/24 mac 00:13:46:e6:f6:87 vyatta@R1#
Notice the plus sign (+) in front of the new statement. This + shows that this statement has been added to the configuration, but the change is not yet committed. The change does not take effect until the configuration is committed by using the commit command.
Another option is to use the compare command to see the change.
vyatta@R1# compare [edit interfaces dataplane dp0p1s1] +address 192.168.1.100/24 vyatta@R1#
You can change the configuration from the root of the configuration tree or use the edit command to navigate to the part of the tree where you want to modify or add a configuration.
The configuration tree is nearly empty when you first startup, except for a few automatically configured nodes. You must create a node for any functionality you want to configure on the system. When a node is created, any default values that exist for its attributes are applied to the node.
Deleting configuration
Use the delete command to delete a configuration statement or a complete configuration node, as in the following example.
vyatta@R1# delete interfaces dataplane dp0p1s1address 192.168.1.100/24
Then use the show command to see the change.
vyatta@R1# show interfaces dataplane dp0p1s1 -address 192.168.1.100/24 mac 00:13:46:e6:f6:87 vyatta@R1#
Notice the minus sign (-) in front of the deleted statement. This - shows that this statement has been deleted from the configuration, but the change is not yet committed. The change does not take effect until configuration is committed by using the commit command.
Another option is to use the compare command to see the change.
vyatta@R1# compare [edit interfaces dataplane dp0p1s1] -address 192.168.1.100/24 vyatta@R1#
Some configuration nodes are mandatory; these nodes cannot be deleted. Some configuration nodes are mandatory but have default values; if you delete one of these nodes, the default value is restored.
Committing configuration changes
In a DANOS vRouter, configuration changes do not take effect until you commit them by using the commit command.
vyatta@R1# commit
A line that contains uncommitted changes is flagged as follows:
> to indicate the line has been modified
+ to indicate the line has been added
- to indicate the line has been deleted
After you commit the changes, the flag disappears, as in the following example.
vyatta@R1# show interfaces dataplane dp0p1s1 -address 192.168.1.100/24 mac 00:13:46:e6:f6:87 vyatta@R1# commit vyatta@R1# show interfaces dataplane dp0p1s1 mac 00:13:46:e6:f6:87 vyatta@R1#
When you commit changes in the configuration mode, the changes are saved to the startup configuration. As a result, the changes are preserved even after a reboot.
If your login username is not a member of the "secrets" login user group and you either save a configuration through the REST API or use the save command, the encrypted passwords in the configuration file are replaced with the ******** placeholder. If you load this configuration, the replaced password fields trigger validation errors because the placeholder does not match the format for an encrypted password. Do not commit this configuration. If you ignore the error message
and perform a commit with this invalid configuration, the passwords are deleted.
Discarding configuration changes
You cannot exit from configuration mode with uncommitted configuration changes; you must either commit the changes or discard them. If you do not want to commit the changes, you can discard them by using the exit discard command.
vyatta@R1# exit Cannot exit: configuration modified. Use 'exit discard' to discard the changes and exit. vyatta@R1# exit discard vyatta@R1:~$