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Diffstat (limited to 'templates')
| -rw-r--r-- | templates/priority | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/templates/priority b/templates/priority index 86eef2c..dfc6d9f 100644 --- a/templates/priority +++ b/templates/priority @@ -1,3 +1,59 @@ +# +# This file controls the processing of the Vyatta config file when it +# is processed by the "load" command and at boot time. This file has +# two purposes. First, it breaks the statements in the Vyatta config +# file into groups that are applied in distinct transactions. Second, +# it defines the order in which these transactions are applied. +# +# Breaking the config file into multiple transactions is important +# because transactions have all-or-nothing semantics. If the file +# were processed in a single transaction, a failure of any service would +# mean that no services would be configured. Processing the config +# file in multiple transactions means that failures in one area do not +# necessary prevent a service in another area from being configured. +# +# Ordering the transactions is important because some services are +# dependent on other services being configured before they are. +# +# The format of this file is as a sequence of one-line entries that +# have the following format: +# +# <priority> <config-sub-tree> +# +# The <priority> field is number in the range 0 - 1000, and is used to +# order the processing of of the config file. +# +# The <config-sub-tree> field is the path to a sub-tree of the +# configuration tree. +# +# The "load" command first sorts the entries in increasing order by +# their <priority> field. We usually try to maintain this file in +# sorted in increasing <priority> order so that we can redily see what +# order the entries will be processed in. Next, the "load" command +# processes each entry, starting from the lowest priority entry, and +# proceeding in increasing prioriy order. For each entry, it checks +# to see if the <config-sub-tree> exists in the config file. If it +# does, it takes the config statements under that sub-tree and removes +# any statements that match a deeper sub-tree that was processed +# earlier or will be processed later. If any statements remain, they +# are applied using "set" commands. Then the entire group is +# committed as a transaction using the "commit" command. After +# processing this entire file, if any un-applied configuration +# statements remain, they are applied in one final transaction. +# +# This process has a few important consequences. First, every +# statement in the config file is applied exactly once. +# +# Second, each line in this file generates at most one transaction. +# +# Third, a config file statement may be applied in a transaction +# before one of its parent nodes is applied. Its parent may be a +# multi-node parameter. An example of this is if the routing protocol +# parameters of an interface are applied before the interface itself +# is applied. In this case, the parent nodes are created in the +# "active config" tree at the time the lower-level node is commited. +# + 200 firewall/group 210 firewall 300 protocols/ospf |