The `Domains=` option in the `[Network]` section did not document its
behaviour when specified repeatedly. In practice the option is additive
(each occurrence accumulates search/routing domains) and assigning an
empty string resets the list, matching the closely related `DNS=`
option. This is implemented by `config_parse_domains()` in
`src/network/networkd-dns.c`, which frees both the search and route
domain sets on an empty `rvalue` and otherwise inserts each
whitespace-separated entry into the corresponding set.
Document this explicitly, using the same wording already used for
`DNS=` in the same man page, so users know repeated assignments are
combined and that an empty value clears them.
Fixes#38740.
Previously, specifying multiple stacked netdevs of the same type required
repeating the corresponding setting, e.g.:
```
[Network]
VLAN=vlan_10
VLAN=vlan_20
VLAN=vlan_30
```
With this change, the same configuration can be written as:
```
[Network]
VLAN=vlan_10 vlan_20 vlan_30
```
Specifying an empty string now also clears all previously assigned stacked
netdevs.
Closes#43103.
This adds an IPv4 counterpart to `IPv6ProxyNDPAddress=` for adding
manual entries to the kernel's IPv4 neighbour proxy table (check via
`ip -4 neighbour show proxy dev <dev>`). systemd-networkd only exposed
`IPv4ProxyARP=` for per-interface `proxy_arp` sysctl (automatic proxy
ARP) with no way to manage manual entries from a .network file.
To avoid duplicating the IPv6 proxy NDP code path, both families are
now combined into a single new `networkd-neighbor-proxy` module. The
IPv6 behaviour is preserved: `IPv6ProxyNDPAddress=` still implies
`IPv6ProxyNDP=yes` unless `IPv6ProxyNDP=` is explicitly disabled and
entries are still dropped if the kernel has no IPv6 support.
The same rule is applied to `IPv4ProxyARPAddress=`. It implies
`IPv4ProxyARP=yes` when the sysctl is not explicitly set and has no
effect if `IPv4ProxyARP=` has been set to false.
This keeps the user model symmetric and predictable across both
families: a single per-address setting that turns on the matching
per-interface sysctl automatically, while still letting system
administrators opt out by setting the boolean explicitly to false.
Note that the IPv4 manual NTF_PROXY entries installed here would
actually function without `proxy_arp` (unlike IPv6, where `proxy_ndp`
gates the manual entries); the implication is kept for symmetry with
`IPv6ProxyNDPAddress=` and is now called out explicitly in the man
page, together with the fact that enabling `proxy_arp` also activates
interface-wide automatic proxy ARP for routed-toward addresses on
connected subnets.
Parser-time validation rejects addresses the kernel would refuse:
the ANY/null address for both families, IPv4 and IPv6 multicast
and the IPv4 limited broadcast 255.255.255.255.
Signed-off-by: Aritra Basu <aritrbas+gh@cisco.com>
- In `systemd.network.xml`, replaced `"without mode"` with `"without static"`
to clarify that if an IPv6 address is specified without the explicit keyword
`static`, then `static` mode is assumed.
- The original wording was ambiguous because "mode" appears multiple
times in the surrounding context (referring to IPv6 link-local address
modes like `eui64`, `static`, etc.).
Fixes: #39754
Then, this deprecates
- BindToInterface=
- RelayTarget=
- RelayAgentCircuitId=
- RelayAgentRemoteId=
settings in [DHCPServer] section.
These are gracefully translated as new settings.
Allow users to allow DHCPv6 unreachable/blackhole routes (installed
for delegated prefixes) into a specific routing table, analogous to
the existing RouteTable= in [DHCPv4] and [IPv6AcceptRA].
The config parser config_parse_dhcp_or_ra_route_table() is extended
with an AF_UNSPEC ltype discriminator for DHCPv6 (AF_INET6 is already
taken by NDISC/RA). link_get_dhcp6_route_table() follows the same
pattern as link_get_dhcp4_route_table() and link_get_ndisc_route_table(),
falling back to the VRF table when not explicitly set.
In dhcp_request_unreachable_route(), the table is applied only for
NETWORK_CONFIG_SOURCE_DHCP6 routes (the uplink unreachable aggregates),
not DHCP_PD routes (per-subnet routes on downstream interfaces), matching
the intent of the feature. The !route->table_set guard avoids overriding
a table already set by the route code.
Document the new setting in systemd.network(5) man page
and add coverage in the networkd integration tests.
Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
and use dedicated knobs for every option used in
former SimpleConnectProperties.
New section is [MobileNetwork] with the following configuration options:
APN=
AllowedAuthenticationMechanisms==
User=
Password=
IPFamily=
AllowRoaming=
PIN=
OperatorId=
MultiPathRoute= can now specify device-only nexthops without a gateway
address, e.g. MultiPathRoute=@wg0. This enables ECMP configurations over
interfaces that don't use gateway addresses, such as WireGuard tunnels.
The syntax is extended from "address[@device] [weight]" to
"[address]@device [weight]". The address is now optional, but at least
one of gateway or device must be specified. The @ symbol must still be
present for device-only routes, making the syntax unambiguous: @wg0
specifies a device, while a bare IP address specifies a gateway.
Device-only nexthops are only available for IPv4 routes. Device-only
multipath routes for IPv6 are not supported by the kernel's netlink
interface and will be rejected with a warning.
This change is fully backwards compatible. All existing configurations
continue to work unchanged, as they always included a gateway address.
Closes#39699.
Add support for an empty Gateway= in [Network] to clear the existing
routes. This change will allow users to remove the default route from a
drop-in file.
`systemd.network(5)` recommends “that each filename is prefixed with a number
smaller than "70" (e.g. 10-eth0.network)”.
Reduce that used by the example accordingly, but stay above the number (`50`)
used in the earlier example for static configuration, so that would take
precedence over the dynamic one if both match for the same network.
Let's synthesize DNS RRs for leases handed out by our DHCP server. This
way local VMs can have resolvable hostnames locally.
This does not implement reverse look ups for now. We can add this
later in similar fashion.
This adds a new `Hostname=` option to the [DHCPServerStaticLease]
section in .network files, allowing an administrator to assign a
specific hostname to a client receiving a static lease.
We automatically select the correct DHCP option to use based on the
format of the provided string:
- Single DNS labels are sent as Option 12.
- Names with multiple DNS labels are sent as Option 81 in wire format.
Fixes: #39634
Implements DHCP option 15 (Domain Name) for systemd-networkd's DHCP
server, allowing administrators to configure the DNS default domain that
clients should use.
This addresses the feature request in issue #37077, where users needed
to manually configure domain names using
SendOption=15:string:example.com as a workaround.
This adds two new configuration options to the [DHCPServer] section:
- EmitDomain= (boolean): whether to send domain name to clients
- Domain= (string): the domain name to send (e.g., "example.com")
Example configuration:
[DHCPServer] EmitDomain=yes Domain=example.com
This eliminates the need for manual workarounds using
SendOption=15:string:...
Fixes#37077
This changes the instances of lexical to lexicographic, thus making it easier
to grep for instances of lexicographic order, since there's only one variant of
the word to consider.
Lexicographic is chosen since there are slightly fewer instances of lexical and
lexicographic seems a better fit than lexical after checking a few
dictionaries.
The words lexical, lexicographic, and lexicographical are synonyms in
computing, meaning an alphabetical order. Both the Oxford dictionary and
Merriam-Webster make no distinction between lexicographic and lexicographical,
with only Wiktionary adding a more precise meaning of
Meeting lexicographical standards or requirements; worthy of being included
in a dictionary. [1]
Since, outside of computing, lexicographic(al) has the more specific meaning
pertaining to lexicography, i.e. the editing or making of dictionaries [2], and
lexical only has this as a secondary meaning after its linguistic meaning [3],
lexicographic fits the meaning of including and ordering entries better.
[1] https://en.wiktionary.org/wiki/lexicographical#English
[2] https://www.merriam-webster.com/dictionary/lexicographic
[3] https://www.oed.com/dictionary/lexical_adj
With 9ccc369ff3, PersistLeases= is
disabled on the host side virtual interfaces for containers.
However, even it is not necessary to save the leases for containers
on a persistent storage, still we should save them on somewhere.
Otherwise, leases will be lost when networkd on the host is restarted
or the host side interface is reconfigured.
This introduce PersistLeases=runtime to save and load leases on runtime
storage.
Add the following network option to enable BOOTP:
[DHCPv4]
Bootp=yes
This will allow a two message request / reply sequence that doesn't
require DHCP message types.
Co-authored-by: Avram Dorfman <dorfman@est.org>
Document .link .network and .netdev file type distinctions in early
introductory text, and document distro-specific need to sync link files
with early-boot copies, see Debian bug 1005282:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1005282 for an
example.
The original timeout of 7 seconds is very long for today's networks. Reduce it
to 200ms. Note that this change also affects IPv4 link-local addressing.
RFC 5227 specifies randomized intervals to avoid that a large number of hosts
powered up at the same time send their message simultaneously. Performing the
conflict detection takes a variable time between 4 and 7 seconds from the
beginning to the first announcement, as shown by the following diagram where P
indicates a probe and A an announcement:
time(s) 0 1 2 3 4 5 6 7 8 9
+---+---+---+---+---+---+---+---+---+
SHORTEST P P P A A
LONGEST P P P A A
The host can't use the address until the first announcement is sent. 7 seconds
is a very long time on modern computers especially considering the fact that
the round-trip time on current LAN technologies is at most few milliseconds.
Section 2.2 of the RFC addresses this matter and hints that a future standard
will adjust those timeouts; however that standard doesn't exist yet.
Make the timeout configurable via a new IPv4DuplicateAddressDetectionTimeoutSec=
option. The intervals defined in the RFC are then scaled proportionally so that
the duration of the conflict detection takes at most the given value. Interval
happening after the first announcement are not scaled, as recommended by the
RFC.
We can run sd-ipv4ll/sd-ipv4acd also on an interface with IFF_NOARP
flag, but that may cause address conflict with other hosts.
Let's enable ARPing when sd-ipv4ll/sd-ipv4acd are enabled unless ARP= is
explicitly disabled.
This fixes some typos in the documentation, both grammar as well as
incorrect field names.
It also changes the casing of CheckSum to Checksum in L2TP to match
other casings.
- Also configures route to the gateway and prefix route in the specified
table, if necessary.
- Also set preferred source address of the route.
Closes#36168.
Since linux commit a35ec8e38cdd1766f29924ca391a01de20163931 ("bridge:
Add MAC Authentication Bypass (MAB) support"), included since v6.2, it
is possible to enable MAC Authentication Bypass for bridge ports. In
this mode the locked port learns again, but the learned fdb entries are
locked, allowing user space to unlock hosts based seen MAC addresses.
This requires learning to be enabled on the port, and link-local
learning disabled for the bridge.
Add support to systemd-network for setting the new attribute for bridge
ports.
Since linux commit a21d9a670d81103db7f788de1a4a4a6e4b891a0b ("net:
bridge: Add support for bridge port in locked mode"), included since
v5.18, it is possible to set bridge ports to locked.
Locked ports do not learn automatically, and discard any traffic from
unknown source MACs. To allow traffic, the userspace authenticator is
expected to create fdb entries for authenticated hosts.
Add support to systemd-network for setting the new attribute for bridge
ports.
With the following, now preferred source address is set to the DHCP
address.
====
[Route]
Gatewa=_dhcp4
Table=100
====
Before:
====
$ ip route show table 100 default
default via 192.168.0.1 dev eth0 proto dhcp metric 1024
====
After:
====
$ ip route show table 100 default
default via 192.168.0.1 dev eth0 proto dhcp src 192.168.0.100 metric 1024
====
To avoid the assignment, this also introduces PreferredSource=no.
Typically, the same client identifier setting is used for all
interfaces. Hence, better to provide the system-wide setting to specify
the client identifier.
Yu Watanabe
lzwind
Aritra Basu
Lennart Poettering
Nandakumar Raghavan
ssahani
Malcolm Frazier
Oleksandr Andrushchenko
Chris Down
Quentin Deslandes
Christoph Anton Mitterer
Lennart Poettering
Dr. David Alan Gilbert
dgengtek
Govind Venugopal
Jörg Behrmann
haxibami
Colin FosterandAvram Dorfman
Zbigniew Jędrzejewski-Szmek
Tim Small
Beniamino Galvani
Erik Larsson
Matteo Croce
Steve Ramage
Luca Boccassi
Jonas Gorski
Jan Engelhardt
andrejpodzimek