doc: Clarify some interface file properties

* Interface file is case-sensitive and all lower-case
 * Clariry netmask handling and fallback

Signed-off-by: Maximilian Wilhelm <max@sdn.clinic>
This commit is contained in:
Maximilian Wilhelm 2021-05-16 17:54:59 +02:00
parent d4907af84f
commit c8a05a742b

View file

@ -11,7 +11,7 @@ interfaces are configured. The file is processed by *ifquery*(8),
*ifup*(8) and *ifdown*(8) to introspect and change system state.
In most cases, syntax from legacy implementations is supported as
well, but that syntax is not discussed here.
well, but that syntax is not discussed in detail here.
# FILE SYNTAX
@ -24,6 +24,8 @@ value combination that is related to an *object*. Triples which
are not associated with an *object* are considered to be part
of the root of the configuration tree.
All keywords are case-sensitive and are expected to be lower-case.
The following is a simple example of a stanza:
```
@ -64,11 +66,11 @@ the system will only respond to certain keywords by default:
*address* _address_
Associates an IPv4 or IPv6 address in CIDR notation with
the parent interface.
*gateway* _address_
Associates an IPv4 or IPv6 address with the parent interface
for use as a default route (gateway).
the parent interface. If an IP address without a prefix
length is given a given _netmask_ attribute is used if present.
If neither a prefix length nor a _netmask_ are given a /24 or /64
prefix length is presumed for IPv4 / IPv6 as of compatibility
reasons to classic ifupdown.
*netmask* _netmask_
Associates a fallback netmask with the parent interface for
@ -83,6 +85,11 @@ the system will only respond to certain keywords by default:
For compatiblity with ifupdown and ifupdown2, _pointopoint_ is
an alias for this parameter.
*gateway* _address_
Associates an IPv4 or IPv6 address with the parent interface
for use as a default route (gateway). This usually is given
once for IPv4 and once for IPv6 (in a Dual-Stack setup).
*link-type* _link-type_
Denotes the link-type of the interface. When set to _dummy_,
the interface is created as a virtual dummy interfaces.