* [PATCH 0/2] docs: net: sysctl documentation improvements
@ 2025-06-12 16:29 Abdelrahman Fekry
2025-06-12 16:29 ` [PATCH 1/2] docs: net: sysctl documentation cleanup Abdelrahman Fekry
2025-06-12 16:29 ` [PATCH 2/2] docs: net: clarify sysctl value constraints Abdelrahman Fekry
0 siblings, 2 replies; 8+ messages in thread
From: Abdelrahman Fekry @ 2025-06-12 16:29 UTC (permalink / raw)
To: davem, edumazet, kuba, pabeni, horms, corbet
Cc: netdev, linux-doc, linux-kernel, skhan, linux-kernel-mentees,
Abdelrahman Fekry
This series cleans up and clarifies networking sysctl documentation,
specially the boolean parameters:
Patch 1: Fixes typos, adds missing defaults, and standardizes
boolean representation.
Patch 2: Adds value constraint clarifications for parameters with u8
implementation details , fixes typos.
Abdelrahman Fekry (2):
docs: net: sysctl documentation cleanup
docs: net: clarify sysctl value constraints
Documentation/networking/ip-sysctl.rst | 87 ++++++++++++++++++++++----
1 file changed, 76 insertions(+), 11 deletions(-)
--
2.25.1
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH 1/2] docs: net: sysctl documentation cleanup
2025-06-12 16:29 [PATCH 0/2] docs: net: sysctl documentation improvements Abdelrahman Fekry
@ 2025-06-12 16:29 ` Abdelrahman Fekry
2025-06-12 17:18 ` Jacob Keller
` (2 more replies)
2025-06-12 16:29 ` [PATCH 2/2] docs: net: clarify sysctl value constraints Abdelrahman Fekry
1 sibling, 3 replies; 8+ messages in thread
From: Abdelrahman Fekry @ 2025-06-12 16:29 UTC (permalink / raw)
To: davem, edumazet, kuba, pabeni, horms, corbet
Cc: netdev, linux-doc, linux-kernel, skhan, linux-kernel-mentees,
Abdelrahman Fekry
I noticed that some boolean parameters have missing default values
(enabled/disabled) in the documentation so i checked the initialization
functions to get their default values, also there was some inconsistency
in the representation. During the process , i stumbled upon a typo in
cipso_rbm_struct_valid instead of cipso_rbm_struct_valid.
- Fixed typo in cipso_rbm_struct_valid
- Added missing default value declarations
- Standardized boolean representation (0/1 with enabled/disabled)
Signed-off-by: Abdelrahman Fekry <abdelrahmanfekry375@gmail.com>
---
Documentation/networking/ip-sysctl.rst | 37 +++++++++++++++++++++-----
1 file changed, 31 insertions(+), 6 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 0f1251cce314..f7ff8c53f412 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -75,7 +75,7 @@ fwmark_reflect - BOOLEAN
If unset, these packets have a fwmark of zero. If set, they have the
fwmark of the packet they are replying to.
- Default: 0
+ Default: 0 (disabled)
fib_multipath_use_neigh - BOOLEAN
Use status of existing neighbor entry when determining nexthop for
@@ -368,7 +368,7 @@ tcp_autocorking - BOOLEAN
queue. Applications can still use TCP_CORK for optimal behavior
when they know how/when to uncork their sockets.
- Default : 1
+ Default : 1 (enabled)
tcp_available_congestion_control - STRING
Shows the available congestion control choices that are registered.
@@ -407,6 +407,12 @@ tcp_congestion_control - STRING
tcp_dsack - BOOLEAN
Allows TCP to send "duplicate" SACKs.
+ Possible values:
+ - 0 disabled
+ - 1 enabled
+
+ Default: 1 (enabled)
tcp_early_retrans - INTEGER
Tail loss probe (TLP) converts RTOs occurring due to tail
@@ -623,6 +629,8 @@ tcp_no_metrics_save - BOOLEAN
increases overall performance, but may sometimes cause performance
degradation. If set, TCP will not cache metrics on closing
connections.
+
+ Default: 0 (disabled)
tcp_no_ssthresh_metrics_save - BOOLEAN
Controls whether TCP saves ssthresh metrics in the route cache.
@@ -684,6 +692,8 @@ tcp_retrans_collapse - BOOLEAN
Bug-to-bug compatibility with some broken printers.
On retransmit try to send bigger packets to work around bugs in
certain TCP stacks.
+
+ Default: 1 (enabled)
tcp_retries1 - INTEGER
This value influences the time, after which TCP decides, that
@@ -739,6 +749,8 @@ tcp_rmem - vector of 3 INTEGERs: min, default, max
tcp_sack - BOOLEAN
Enable select acknowledgments (SACKS).
+
+ Default: 1 (enabled)
tcp_comp_sack_delay_ns - LONG INTEGER
TCP tries to reduce number of SACK sent, using a timer
@@ -766,7 +778,7 @@ tcp_backlog_ack_defer - BOOLEAN
one ACK for the whole queue. This helps to avoid potential
long latencies at end of a TCP socket syscall.
- Default : true
+ Default : 1 (enabled)
tcp_slow_start_after_idle - BOOLEAN
If set, provide RFC2861 behavior and time out the congestion
@@ -781,7 +793,7 @@ tcp_stdurg - BOOLEAN
Most hosts use the older BSD interpretation, so if you turn this on
Linux might not communicate correctly with them.
- Default: FALSE
+ Default: 0 (disabled)
tcp_synack_retries - INTEGER
Number of times SYNACKs for a passive TCP connection attempt will
@@ -1018,6 +1030,10 @@ tcp_tw_reuse_delay - UNSIGNED INTEGER
tcp_window_scaling - BOOLEAN
Enable window scaling as defined in RFC1323.
+ - 0 - Disabled.
+ - 1 - Enabled.
+
+ Default: 1 (enabled)
tcp_shrink_window - BOOLEAN
This changes how the TCP receive window is calculated.
@@ -1160,7 +1176,7 @@ tcp_plb_enabled - BOOLEAN
congestion measure (e.g. ce_ratio). PLB needs a congestion measure to
make repathing decisions.
- Default: FALSE
+ Default: 0 (disabled)
tcp_plb_idle_rehash_rounds - INTEGER
Number of consecutive congested rounds (RTT) seen after which
@@ -1352,7 +1368,7 @@ cipso_rbm_optfmt - BOOLEAN
Default: 0
-cipso_rbm_structvalid - BOOLEAN
+cipso_rbm_strictvalid - BOOLEAN
If set, do a very strict check of the CIPSO option when
ip_options_compile() is called. If unset, relax the checks done during
ip_options_compile(). Either way is "safe" as errors are caught else
@@ -1933,10 +1949,15 @@ mcast_resolicit - INTEGER
disable_policy - BOOLEAN
Disable IPSEC policy (SPD) for this interface
+
+ Default: 0
+
disable_xfrm - BOOLEAN
Disable IPSEC encryption on this interface, whatever the policy
+ Default: 0
+
igmpv2_unsolicited_report_interval - INTEGER
The interval in milliseconds in which the next unsolicited
IGMPv1 or IGMPv2 report retransmit will take place.
@@ -1951,11 +1972,15 @@ igmpv3_unsolicited_report_interval - INTEGER
ignore_routes_with_linkdown - BOOLEAN
Ignore routes whose link is down when performing a FIB lookup.
+
+ Default: 0 (disabled)
promote_secondaries - BOOLEAN
When a primary IP address is removed from this interface
promote a corresponding secondary IP address instead of
removing all the corresponding secondary IP addresses.
+
+ Default: 0 (disabled)
drop_unicast_in_l2_multicast - BOOLEAN
Drop any unicast IP packets that are received in link-layer
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 2/2] docs: net: clarify sysctl value constraints
2025-06-12 16:29 [PATCH 0/2] docs: net: sysctl documentation improvements Abdelrahman Fekry
2025-06-12 16:29 ` [PATCH 1/2] docs: net: sysctl documentation cleanup Abdelrahman Fekry
@ 2025-06-12 16:29 ` Abdelrahman Fekry
2025-06-12 17:19 ` Jacob Keller
1 sibling, 1 reply; 8+ messages in thread
From: Abdelrahman Fekry @ 2025-06-12 16:29 UTC (permalink / raw)
To: davem, edumazet, kuba, pabeni, horms, corbet
Cc: netdev, linux-doc, linux-kernel, skhan, linux-kernel-mentees,
Abdelrahman Fekry
So, i also noticed that some of the parameters represented
as boolean have no value constrain checks and accept integer
values due to u8 implementation, so i wrote a note for every
boolean parameter that have no constrain checks in code. and
fixed a typo in fmwark instead of fwmark.
Added notes for 19 confirmed parameters,
Verified by code inspection and runtime testing.
Signed-off-by: Abdelrahman Fekry <abdelrahmanfekry375@gmail.com>
---
Documentation/networking/ip-sysctl.rst | 50 +++++++++++++++++++++++---
1 file changed, 45 insertions(+), 5 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index f7ff8c53f412..99e786915204 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -68,6 +68,8 @@ ip_forward_use_pmtu - BOOLEAN
- 0 - disabled
- 1 - enabled
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
fwmark_reflect - BOOLEAN
Controls the fwmark of kernel-generated IPv4 reply packets that are not
@@ -89,6 +91,8 @@ fib_multipath_use_neigh - BOOLEAN
- 0 - disabled
- 1 - enabled
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
fib_multipath_hash_policy - INTEGER
Controls which hash policy to use for multipath routes. Only valid
@@ -489,6 +493,8 @@ tcp_fwmark_accept - BOOLEAN
unaffected.
Default: 0
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
tcp_invalid_ratelimit - INTEGER
Limit the maximal rate for sending duplicate acknowledgments
@@ -603,6 +609,8 @@ tcp_moderate_rcvbuf - BOOLEAN
automatically size the buffer (no greater than tcp_rmem[2]) to
match the size required by the path for full throughput. Enabled by
default.
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
tcp_mtu_probing - INTEGER
Controls TCP Packetization-Layer Path MTU Discovery. Takes three
@@ -636,6 +644,8 @@ tcp_no_ssthresh_metrics_save - BOOLEAN
Controls whether TCP saves ssthresh metrics in the route cache.
Default is 1, which disables ssthresh metrics.
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
tcp_orphan_retries - INTEGER
This value influences the timeout of a locally closed TCP connection,
@@ -703,7 +713,9 @@ tcp_retries1 - INTEGER
RFC 1122 recommends at least 3 retransmissions, which is the
default.
-
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
+
tcp_retries2 - INTEGER
This value influences the timeout of an alive TCP connection,
when RTO retransmissions remain unacknowledged.
@@ -751,6 +763,8 @@ tcp_sack - BOOLEAN
Enable select acknowledgments (SACKS).
Default: 1 (enabled)
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
tcp_comp_sack_delay_ns - LONG INTEGER
TCP tries to reduce number of SACK sent, using a timer
@@ -787,6 +801,8 @@ tcp_slow_start_after_idle - BOOLEAN
be timed out after an idle period.
Default: 1
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
tcp_stdurg - BOOLEAN
Use the Host requirements interpretation of the TCP urgent pointer field.
@@ -794,6 +810,8 @@ tcp_stdurg - BOOLEAN
Linux might not communicate correctly with them.
Default: 0 (disabled)
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
tcp_synack_retries - INTEGER
Number of times SYNACKs for a passive TCP connection attempt will
@@ -1034,6 +1052,8 @@ tcp_window_scaling - BOOLEAN
- 1 - Enabled.
Default: 1 (enabled)
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
tcp_shrink_window - BOOLEAN
This changes how the TCP receive window is calculated.
@@ -1049,6 +1069,8 @@ tcp_shrink_window - BOOLEAN
scaling factor is also in effect.
Default: 0
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
tcp_wmem - vector of 3 INTEGERs: min, default, max
min: Amount of memory reserved for send buffers for TCP sockets.
@@ -1104,7 +1126,9 @@ tcp_thin_linear_timeouts - BOOLEAN
Documentation/networking/tcp-thin.rst
Default: 0
-
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
+
tcp_limit_output_bytes - INTEGER
Controls TCP Small Queue limit per tcp socket.
TCP bulk sender tends to increase packets in flight until it
@@ -1367,6 +1391,9 @@ cipso_rbm_optfmt - BOOLEAN
categories in order to make the packet data 32-bit aligned.
Default: 0
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
+
cipso_rbm_strictvalid - BOOLEAN
If set, do a very strict check of the CIPSO option when
@@ -1377,6 +1404,9 @@ cipso_rbm_strictvalid - BOOLEAN
with other implementations that require strict checking.
Default: 0
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
+
IP Variables
============
@@ -1437,6 +1467,9 @@ ip_nonlocal_bind - BOOLEAN
which can be quite useful - but may break some applications.
Default: 0
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
+
ip_autobind_reuse - BOOLEAN
By default, bind() does not select the ports automatically even if
@@ -1447,6 +1480,8 @@ ip_autobind_reuse - BOOLEAN
option should only be set by experts.
Default: 0
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
+
ip_dynaddr - INTEGER
If set non-zero, enables support for dynamic addresses.
If set to a non-zero value larger than 1, a kernel log
@@ -1476,13 +1511,16 @@ tcp_early_demux - BOOLEAN
Enable early demux for established TCP sockets.
Default: 1
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
+
udp_early_demux - BOOLEAN
Enable early demux for connected UDP sockets. Disable this if
your system could experience more unconnected load.
Default: 1
-
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
+
icmp_echo_ignore_all - BOOLEAN
If set non-zero, then the kernel will ignore all ICMP ECHO
requests sent to it.
@@ -1815,7 +1853,7 @@ src_valid_mark - BOOLEAN
lookup. This permits rp_filter to function when the fwmark is
used for routing traffic in both directions.
- This setting also affects the utilization of fmwark when
+ This setting also affects the utilization of fwmark when
performing source address selection for ICMP replies, or
determining addresses stored for the IPOPT_TS_TSANDADDR and
IPOPT_RR IP options.
@@ -2324,7 +2362,9 @@ fwmark_reflect - BOOLEAN
fwmark of the packet they are replying to.
Default: 0
-
+
+ note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
+
``conf/interface/*``:
Change special settings per interface.
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] docs: net: sysctl documentation cleanup
2025-06-12 16:29 ` [PATCH 1/2] docs: net: sysctl documentation cleanup Abdelrahman Fekry
@ 2025-06-12 17:18 ` Jacob Keller
2025-06-13 6:07 ` ALOK TIWARI
2025-06-14 9:25 ` [PATCH v2 " Abdelrahman Fekry
2 siblings, 0 replies; 8+ messages in thread
From: Jacob Keller @ 2025-06-12 17:18 UTC (permalink / raw)
To: Abdelrahman Fekry, davem, edumazet, kuba, pabeni, horms, corbet
Cc: netdev, linux-doc, linux-kernel, skhan, linux-kernel-mentees
On 6/12/2025 9:29 AM, Abdelrahman Fekry wrote:
> I noticed that some boolean parameters have missing default values
> (enabled/disabled) in the documentation so i checked the initialization
> functions to get their default values, also there was some inconsistency
> in the representation. During the process , i stumbled upon a typo in
> cipso_rbm_struct_valid instead of cipso_rbm_struct_valid.
>
> - Fixed typo in cipso_rbm_struct_valid
> - Added missing default value declarations
> - Standardized boolean representation (0/1 with enabled/disabled)
>
> Signed-off-by: Abdelrahman Fekry <abdelrahmanfekry375@gmail.com>
> ---
Thank you for the documentation improvements! I do think its a bit more
clear to include the "(enabled)" or "(disabled)".
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
> Documentation/networking/ip-sysctl.rst | 37 +++++++++++++++++++++-----
> 1 file changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
> index 0f1251cce314..f7ff8c53f412 100644
> --- a/Documentation/networking/ip-sysctl.rst
> +++ b/Documentation/networking/ip-sysctl.rst
> @@ -407,6 +407,12 @@ tcp_congestion_control - STRING
>
> tcp_dsack - BOOLEAN
> Allows TCP to send "duplicate" SACKs.
> + Possible values:
> + - 0 disabled
> + - 1 enabled
> +
> + Default: 1 (enabled)
>
Would it make sense to use "0 (disabled)" and "1 (enabled)" with
parenthesis for consistency with the default value?
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 2/2] docs: net: clarify sysctl value constraints
2025-06-12 16:29 ` [PATCH 2/2] docs: net: clarify sysctl value constraints Abdelrahman Fekry
@ 2025-06-12 17:19 ` Jacob Keller
0 siblings, 0 replies; 8+ messages in thread
From: Jacob Keller @ 2025-06-12 17:19 UTC (permalink / raw)
To: Abdelrahman Fekry, davem, edumazet, kuba, pabeni, horms, corbet
Cc: netdev, linux-doc, linux-kernel, skhan, linux-kernel-mentees
On 6/12/2025 9:29 AM, Abdelrahman Fekry wrote:
> So, i also noticed that some of the parameters represented
> as boolean have no value constrain checks and accept integer
> values due to u8 implementation, so i wrote a note for every
> boolean parameter that have no constrain checks in code. and
> fixed a typo in fmwark instead of fwmark.
>
> Added notes for 19 confirmed parameters,
> Verified by code inspection and runtime testing.
>
> Signed-off-by: Abdelrahman Fekry <abdelrahmanfekry375@gmail.com>
> ---
> Documentation/networking/ip-sysctl.rst | 50 +++++++++++++++++++++++---
> 1 file changed, 45 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
> index f7ff8c53f412..99e786915204 100644
> --- a/Documentation/networking/ip-sysctl.rst
> +++ b/Documentation/networking/ip-sysctl.rst
> @@ -68,6 +68,8 @@ ip_forward_use_pmtu - BOOLEAN
>
> - 0 - disabled
> - 1 - enabled
> +
> + note: Accepts integer values (0-255) but only 0/1 have defined behaviour.
>
Hm. In many cases any non-zero value might be interpreted as "enabled" I
suppose that is simply "undefined behavior"?
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] docs: net: sysctl documentation cleanup
2025-06-12 16:29 ` [PATCH 1/2] docs: net: sysctl documentation cleanup Abdelrahman Fekry
2025-06-12 17:18 ` Jacob Keller
@ 2025-06-13 6:07 ` ALOK TIWARI
2025-06-14 9:25 ` [PATCH v2 " Abdelrahman Fekry
2 siblings, 0 replies; 8+ messages in thread
From: ALOK TIWARI @ 2025-06-13 6:07 UTC (permalink / raw)
To: Abdelrahman Fekry, davem, edumazet, kuba, pabeni, horms, corbet
Cc: netdev, linux-doc, linux-kernel, skhan, linux-kernel-mentees
On 12-06-2025 21:59, Abdelrahman Fekry wrote:
> I noticed that some boolean parameters have missing default values
> (enabled/disabled) in the documentation so i checked the initialization
> functions to get their default values, also there was some inconsistency
> in the representation. During the process , i stumbled upon a typo in
> cipso_rbm_struct_valid instead of cipso_rbm_struct_valid.
>
> - Fixed typo in cipso_rbm_struct_valid
> - Added missing default value declarations
> - Standardized boolean representation (0/1 with enabled/disabled)
>
> Signed-off-by: Abdelrahman Fekry <abdelrahmanfekry375@gmail.com>
> ---
> Documentation/networking/ip-sysctl.rst | 37 +++++++++++++++++++++-----
> 1 file changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
> index 0f1251cce314..f7ff8c53f412 100644
> --- a/Documentation/networking/ip-sysctl.rst
> +++ b/Documentation/networking/ip-sysctl.rst
> @@ -75,7 +75,7 @@ fwmark_reflect - BOOLEAN
> If unset, these packets have a fwmark of zero. If set, they have the
> fwmark of the packet they are replying to.
>
> - Default: 0
> + Default: 0 (disabled)
>
> fib_multipath_use_neigh - BOOLEAN
> Use status of existing neighbor entry when determining nexthop for
> @@ -368,7 +368,7 @@ tcp_autocorking - BOOLEAN
> queue. Applications can still use TCP_CORK for optimal behavior
> when they know how/when to uncork their sockets.
>
> - Default : 1
> + Default : 1 (enabled)
for consistency
remove extra space before colon
Default: 1 (enabled)
>
> tcp_available_congestion_control - STRING
> Shows the available congestion control choices that are registered.
> @@ -407,6 +407,12 @@ tcp_congestion_control - STRING
>
> tcp_dsack - BOOLEAN
> Allows TCP to send "duplicate" SACKs.
> + Possible values:
> + - 0 disabled
> + - 1 enabled
> +
> + Default: 1 (enabled)
>
> tcp_early_retrans - INTEGER
> Tail loss probe (TLP) converts RTOs occurring due to tail
> @@ -623,6 +629,8 @@ tcp_no_metrics_save - BOOLEAN
> increases overall performance, but may sometimes cause performance
> degradation. If set, TCP will not cache metrics on closing
> connections.
> +
> + Default: 0 (disabled)
>
> tcp_no_ssthresh_metrics_save - BOOLEAN
> Controls whether TCP saves ssthresh metrics in the route cache.
> @@ -684,6 +692,8 @@ tcp_retrans_collapse - BOOLEAN
> Bug-to-bug compatibility with some broken printers.
> On retransmit try to send bigger packets to work around bugs in
> certain TCP stacks.
> +
> + Default: 1 (enabled)
>
> tcp_retries1 - INTEGER
> This value influences the time, after which TCP decides, that
> @@ -739,6 +749,8 @@ tcp_rmem - vector of 3 INTEGERs: min, default, max
>
> tcp_sack - BOOLEAN
> Enable select acknowledgments (SACKS).
> +
> + Default: 1 (enabled)
>
> tcp_comp_sack_delay_ns - LONG INTEGER
> TCP tries to reduce number of SACK sent, using a timer
> @@ -766,7 +778,7 @@ tcp_backlog_ack_defer - BOOLEAN
> one ACK for the whole queue. This helps to avoid potential
> long latencies at end of a TCP socket syscall.
>
> - Default : true
> + Default : 1 (enabled)
Default: 1 (enabled)
>
> tcp_slow_start_after_idle - BOOLEAN
> If set, provide RFC2861 behavior and time out the congestion
> @@ -781,7 +793,7 @@ tcp_stdurg - BOOLEAN
> Most hosts use the older BSD interpretation, so if you turn this on
> Linux might not communicate correctly with them.
Thanks,
Alok
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2 1/2] docs: net: sysctl documentation cleanup
2025-06-12 16:29 ` [PATCH 1/2] docs: net: sysctl documentation cleanup Abdelrahman Fekry
2025-06-12 17:18 ` Jacob Keller
2025-06-13 6:07 ` ALOK TIWARI
@ 2025-06-14 9:25 ` Abdelrahman Fekry
2025-06-14 17:46 ` Jakub Kicinski
2 siblings, 1 reply; 8+ messages in thread
From: Abdelrahman Fekry @ 2025-06-14 9:25 UTC (permalink / raw)
To: corbet, davem, edumazet, horms, kuba, pabeni
Cc: abdelrahmanfekry375, linux-doc, linux-kernel-mentees,
linux-kernel, netdev, skhan
Changes in v2:
- Deleted space before colon for consistency
- Standardized more boolean representation (0/1 with enabled/disabled)
Signed-off-by: Abdelrahman Fekry <abdelrahmanfekry375@gmail.com>
---
Documentation/networking/ip-sysctl.rst | 47 ++++++++++++++++++++------
1 file changed, 37 insertions(+), 10 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 0f1251cce314..68778532faa5 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -8,14 +8,16 @@ IP Sysctl
==============================
ip_forward - BOOLEAN
- - 0 - disabled (default)
- - not 0 - enabled
+ - 0 (disabled)
+ - not 0 (enabled)
Forward Packets between interfaces.
This variable is special, its change resets all configuration
parameters to their default state (RFC1122 for hosts, RFC1812
for routers)
+
+ Default: 0 (disabled)
ip_default_ttl - INTEGER
Default value of TTL field (Time To Live) for outgoing (but not
@@ -75,7 +77,7 @@ fwmark_reflect - BOOLEAN
If unset, these packets have a fwmark of zero. If set, they have the
fwmark of the packet they are replying to.
- Default: 0
+ Default: 0 (disabled)
fib_multipath_use_neigh - BOOLEAN
Use status of existing neighbor entry when determining nexthop for
@@ -368,7 +370,7 @@ tcp_autocorking - BOOLEAN
queue. Applications can still use TCP_CORK for optimal behavior
when they know how/when to uncork their sockets.
- Default : 1
+ Default: 1 (enabled)
tcp_available_congestion_control - STRING
Shows the available congestion control choices that are registered.
@@ -407,6 +409,12 @@ tcp_congestion_control - STRING
tcp_dsack - BOOLEAN
Allows TCP to send "duplicate" SACKs.
+
+ Possible values:
+ - 0 (disabled)
+ - 1 (enabled)
+
+ Default: 1 (enabled)
tcp_early_retrans - INTEGER
Tail loss probe (TLP) converts RTOs occurring due to tail
@@ -623,6 +631,8 @@ tcp_no_metrics_save - BOOLEAN
increases overall performance, but may sometimes cause performance
degradation. If set, TCP will not cache metrics on closing
connections.
+
+ Default: 0 (disabled)
tcp_no_ssthresh_metrics_save - BOOLEAN
Controls whether TCP saves ssthresh metrics in the route cache.
@@ -684,6 +694,8 @@ tcp_retrans_collapse - BOOLEAN
Bug-to-bug compatibility with some broken printers.
On retransmit try to send bigger packets to work around bugs in
certain TCP stacks.
+
+ Default: 1 (enabled)
tcp_retries1 - INTEGER
This value influences the time, after which TCP decides, that
@@ -739,6 +751,8 @@ tcp_rmem - vector of 3 INTEGERs: min, default, max
tcp_sack - BOOLEAN
Enable select acknowledgments (SACKS).
+
+ Default: 1 (enabled)
tcp_comp_sack_delay_ns - LONG INTEGER
TCP tries to reduce number of SACK sent, using a timer
@@ -766,7 +780,7 @@ tcp_backlog_ack_defer - BOOLEAN
one ACK for the whole queue. This helps to avoid potential
long latencies at end of a TCP socket syscall.
- Default : true
+ Default: 1 (enabled)
tcp_slow_start_after_idle - BOOLEAN
If set, provide RFC2861 behavior and time out the congestion
@@ -781,7 +795,7 @@ tcp_stdurg - BOOLEAN
Most hosts use the older BSD interpretation, so if you turn this on
Linux might not communicate correctly with them.
- Default: FALSE
+ Default: 0 (disabled)
tcp_synack_retries - INTEGER
Number of times SYNACKs for a passive TCP connection attempt will
@@ -1018,6 +1032,10 @@ tcp_tw_reuse_delay - UNSIGNED INTEGER
tcp_window_scaling - BOOLEAN
Enable window scaling as defined in RFC1323.
+ - 0 (disabled)
+ - 1 (enabled)
+
+ Default: 1 (enabled)
tcp_shrink_window - BOOLEAN
This changes how the TCP receive window is calculated.
@@ -1160,7 +1178,7 @@ tcp_plb_enabled - BOOLEAN
congestion measure (e.g. ce_ratio). PLB needs a congestion measure to
make repathing decisions.
- Default: FALSE
+ Default: 0 (disabled)
tcp_plb_idle_rehash_rounds - INTEGER
Number of consecutive congested rounds (RTT) seen after which
@@ -1352,7 +1370,7 @@ cipso_rbm_optfmt - BOOLEAN
Default: 0
-cipso_rbm_structvalid - BOOLEAN
+cipso_rbm_strictvalid - BOOLEAN
If set, do a very strict check of the CIPSO option when
ip_options_compile() is called. If unset, relax the checks done during
ip_options_compile(). Either way is "safe" as errors are caught else
@@ -1543,7 +1561,7 @@ icmp_ignore_bogus_error_responses - BOOLEAN
If this is set to TRUE, the kernel will not give such warnings, which
will avoid log file clutter.
- Default: 1
+ Default: 1 (enabled)
icmp_errors_use_inbound_ifaddr - BOOLEAN
@@ -1560,7 +1578,7 @@ icmp_errors_use_inbound_ifaddr - BOOLEAN
then the primary address of the first non-loopback interface that
has one will be used regardless of this setting.
- Default: 0
+ Default: 0 (disabled)
igmp_max_memberships - INTEGER
Change the maximum number of multicast groups we can subscribe to.
@@ -1933,10 +1951,15 @@ mcast_resolicit - INTEGER
disable_policy - BOOLEAN
Disable IPSEC policy (SPD) for this interface
+
+ Default: 0
+
disable_xfrm - BOOLEAN
Disable IPSEC encryption on this interface, whatever the policy
+ Default: 0
+
igmpv2_unsolicited_report_interval - INTEGER
The interval in milliseconds in which the next unsolicited
IGMPv1 or IGMPv2 report retransmit will take place.
@@ -1951,11 +1974,15 @@ igmpv3_unsolicited_report_interval - INTEGER
ignore_routes_with_linkdown - BOOLEAN
Ignore routes whose link is down when performing a FIB lookup.
+
+ Default: 0 (disabled)
promote_secondaries - BOOLEAN
When a primary IP address is removed from this interface
promote a corresponding secondary IP address instead of
removing all the corresponding secondary IP addresses.
+
+ Default: 0 (disabled)
drop_unicast_in_l2_multicast - BOOLEAN
Drop any unicast IP packets that are received in link-layer
--
2.25.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v2 1/2] docs: net: sysctl documentation cleanup
2025-06-14 9:25 ` [PATCH v2 " Abdelrahman Fekry
@ 2025-06-14 17:46 ` Jakub Kicinski
0 siblings, 0 replies; 8+ messages in thread
From: Jakub Kicinski @ 2025-06-14 17:46 UTC (permalink / raw)
To: Abdelrahman Fekry
Cc: corbet, davem, edumazet, horms, pabeni, linux-doc,
linux-kernel-mentees, linux-kernel, netdev, skhan
On Sat, 14 Jun 2025 12:25:42 +0300 Abdelrahman Fekry wrote:
> Changes in v2:
> - Deleted space before colon for consistency
> - Standardized more boolean representation (0/1 with enabled/disabled)
You need to repost the entire series. Make sure you read:
https://www.kernel.org/doc/html/next/process/maintainer-netdev.html
before you do.
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2025-06-14 17:46 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-06-12 16:29 [PATCH 0/2] docs: net: sysctl documentation improvements Abdelrahman Fekry
2025-06-12 16:29 ` [PATCH 1/2] docs: net: sysctl documentation cleanup Abdelrahman Fekry
2025-06-12 17:18 ` Jacob Keller
2025-06-13 6:07 ` ALOK TIWARI
2025-06-14 9:25 ` [PATCH v2 " Abdelrahman Fekry
2025-06-14 17:46 ` Jakub Kicinski
2025-06-12 16:29 ` [PATCH 2/2] docs: net: clarify sysctl value constraints Abdelrahman Fekry
2025-06-12 17:19 ` Jacob Keller
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