ip_forward - BOOLEAN
0 - disabled (default)
- not 0 - enabled
+ not 0 - enabled
Forward Packets between interfaces.
IP Fragmentation:
ipfrag_high_thresh - INTEGER
- Maximum memory used to reassemble IP fragments. When
+ Maximum memory used to reassemble IP fragments. When
ipfrag_high_thresh bytes of memory is allocated for this purpose,
the fragment handler will toss packets until ipfrag_low_thresh
is reached.
-
+
ipfrag_low_thresh - INTEGER
- See ipfrag_high_thresh
+ See ipfrag_high_thresh
ipfrag_time - INTEGER
- Time in seconds to keep an IP fragment in memory.
+ Time in seconds to keep an IP fragment in memory.
ipfrag_secret_interval - INTEGER
- Regeneration interval (in seconds) of the hash secret (or lifetime
+ Regeneration interval (in seconds) of the hash secret (or lifetime
for the hash secret) for IP fragments.
Default: 600
ipfrag_max_dist - INTEGER
- ipfrag_max_dist is a non-negative integer value which defines the
- maximum "disorder" which is allowed among fragments which share a
- common IP source address. Note that reordering of packets is
- not unusual, but if a large number of fragments arrive from a source
- IP address while a particular fragment queue remains incomplete, it
- probably indicates that one or more fragments belonging to that queue
- have been lost. When ipfrag_max_dist is positive, an additional check
- is done on fragments before they are added to a reassembly queue - if
- ipfrag_max_dist (or more) fragments have arrived from a particular IP
- address between additions to any IP fragment queue using that source
- address, it's presumed that one or more fragments in the queue are
- lost. The existing fragment queue will be dropped, and a new one
+ ipfrag_max_dist is a non-negative integer value which defines the
+ maximum "disorder" which is allowed among fragments which share a
+ common IP source address. Note that reordering of packets is
+ not unusual, but if a large number of fragments arrive from a source
+ IP address while a particular fragment queue remains incomplete, it
+ probably indicates that one or more fragments belonging to that queue
+ have been lost. When ipfrag_max_dist is positive, an additional check
+ is done on fragments before they are added to a reassembly queue - if
+ ipfrag_max_dist (or more) fragments have arrived from a particular IP
+ address between additions to any IP fragment queue using that source
+ address, it's presumed that one or more fragments in the queue are
+ lost. The existing fragment queue will be dropped, and a new one
started. An ipfrag_max_dist value of zero disables this check.
Using a very small value, e.g. 1 or 2, for ipfrag_max_dist can
result in unnecessarily dropping fragment queues when normal
- reordering of packets occurs, which could lead to poor application
- performance. Using a very large value, e.g. 50000, increases the
- likelihood of incorrectly reassembling IP fragments that originate
+ reordering of packets occurs, which could lead to poor application
+ performance. Using a very large value, e.g. 50000, increases the
+ likelihood of incorrectly reassembling IP fragments that originate
from different IP datagrams, which could result in data corruption.
Default: 64
INET peer storage:
inet_peer_threshold - INTEGER
- The approximate size of the storage. Starting from this threshold
+ The approximate size of the storage. Starting from this threshold
entries will be thrown aggressively. This threshold also determines
entries' time-to-live and time intervals between garbage collection
passes. More entries, less time-to-live, less GC interval.
in effect under low (or absent) memory pressure on the pool.
Measured in seconds.
-TCP variables:
+TCP variables:
somaxconn - INTEGER
Limit of socket listen() backlog, known in userspace as SOMAXCONN.
tcp_reordering - INTEGER
Maximal reordering of packets in a TCP stream.
- Default: 3
+ Default: 3
tcp_retrans_collapse - BOOLEAN
Bug-to-bug compatibility with some broken printers.
ip_local_port_range - 2 INTEGERS
Defines the local port range that is used by TCP and UDP to
- choose the local port. The first number is the first, the
+ choose the local port. The first number is the first, the
second the last local port number. Default value depends on
amount of memory available on the system:
> 128Mb 32768-61000
If zero, icmp error messages are sent with the primary address of
the exiting interface.
-
+
If non-zero, the message will be sent with the primary address of
the interface that received the packet that caused the icmp error.
This is the behaviour network many administrators will expect from
a router. And it can make debugging complicated network layouts
- much easier.
+ much easier.
Note that if no primary address exists for the interface selected,
then the primary address of the first non-loopback interface that
Change the maximum number of multicast groups we can subscribe to.
Default: 20
-conf/interface/* changes special settings per interface (where "interface" is
+conf/interface/* changes special settings per interface (where "interface" is
the name of your network interface)
conf/all/* is special, changes the settings for all interfaces
accept_redirects - BOOLEAN
Accept ICMP redirect messages.
accept_redirects for the interface will be enabled if:
- - both conf/{all,interface}/accept_redirects are TRUE in the case forwarding
- for the interface is enabled
+ - both conf/{all,interface}/accept_redirects are TRUE in the case
+ forwarding for the interface is enabled
or
- - at least one of conf/{all,interface}/accept_redirects is TRUE in the case
- forwarding for the interface is disabled
+ - at least one of conf/{all,interface}/accept_redirects is TRUE in the
+ case forwarding for the interface is disabled
accept_redirects for the interface will be disabled otherwise
default TRUE (host)
FALSE (router)
mc_forwarding - BOOLEAN
Do multicast routing. The kernel needs to be compiled with CONFIG_MROUTE
and a multicast routing daemon is required.
- conf/all/mc_forwarding must also be set to TRUE to enable multicast routing
- for the interface
+ conf/all/mc_forwarding must also be set to TRUE to enable multicast
+ routing for the interface
medium_id - INTEGER
Integer value used to differentiate the devices by the medium they
the broadcast packets are received only on one of them.
The default value 0 means that the device is the only interface
to its medium, value of -1 means that medium is not known.
-
+
Currently, it is used to change the proxy_arp behavior:
the proxy_arp feature is enabled for packets forwarded between
two devices attached to different media.
and if the source address is not reachable via any interface
the packet check will fail.
- Current recommended practice in RFC3704 is to enable strict mode
+ Current recommended practice in RFC3704 is to enable strict mode
to prevent IP spoofing from DDos attacks. If using asymmetric routing
- or other complicated routing, then loose mode is recommended.
+ or other complicated routing, then loose mode is recommended.
conf/all/rp_filter must also be set to non-zero to do source validation
on the interface
bindv6only - BOOLEAN
Default value for IPV6_V6ONLY socket option,
- which restricts use of the IPv6 socket to IPv6 communication
+ which restricts use of the IPv6 socket to IPv6 communication
only.
TRUE: disable IPv4-mapped address feature
FALSE: enable IPv4-mapped address feature
IPv6 Fragmentation:
ip6frag_high_thresh - INTEGER
- Maximum memory used to reassemble IPv6 fragments. When
+ Maximum memory used to reassemble IPv6 fragments. When
ip6frag_high_thresh bytes of memory is allocated for this purpose,
the fragment handler will toss packets until ip6frag_low_thresh
is reached.
-
+
ip6frag_low_thresh - INTEGER
- See ip6frag_high_thresh
+ See ip6frag_high_thresh
ip6frag_time - INTEGER
Time in seconds to keep an IPv6 fragment in memory.
ip6frag_secret_interval - INTEGER
- Regeneration interval (in seconds) of the hash secret (or lifetime
+ Regeneration interval (in seconds) of the hash secret (or lifetime
for the hash secret) for IPv6 fragments.
Default: 600
conf/all/*:
- Change all the interface-specific settings.
+ Change all the interface-specific settings.
[XXX: Other special features than forwarding?]
conf/all/forwarding - BOOLEAN
- Enable global IPv6 forwarding between all interfaces.
+ Enable global IPv6 forwarding between all interfaces.
- IPv4 and IPv6 work differently here; e.g. netfilter must be used
+ IPv4 and IPv6 work differently here; e.g. netfilter must be used
to control which interfaces may forward packets and which not.
- This also sets all interfaces' Host/Router setting
+ This also sets all interfaces' Host/Router setting
'forwarding' to the specified value. See below for details.
This referred to as global forwarding.
conf/interface/*:
Change special settings per interface.
- The functional behaviour for certain settings is different
+ The functional behaviour for certain settings is different
depending on whether local forwarding is enabled or not.
accept_ra - BOOLEAN
Accept Router Advertisements; autoconfigure using them.
-
+
Functional default: enabled if local forwarding is disabled.
disabled if local forwarding is enabled.
Default: 0
autoconf - BOOLEAN
- Autoconfigure addresses using Prefix Information in Router
+ Autoconfigure addresses using Prefix Information in Router
Advertisements.
Functional default: enabled if accept_ra_pinfo is enabled.
dad_transmits - INTEGER
The amount of Duplicate Address Detection probes to send.
Default: 1
-
+
forwarding - BOOLEAN
- Configure interface-specific Host/Router behaviour.
+ Configure interface-specific Host/Router behaviour.
- Note: It is recommended to have the same setting on all
+ Note: It is recommended to have the same setting on all
interfaces; mixed router/host scenarios are rather uncommon.
FALSE:
1. IsRouter flag is not set in Neighbour Advertisements.
2. Router Solicitations are being sent when necessary.
- 3. If accept_ra is TRUE (default), accept Router
+ 3. If accept_ra is TRUE (default), accept Router
Advertisements (and do autoconfiguration).
4. If accept_redirects is TRUE (default), accept Redirects.
TRUE:
- If local forwarding is enabled, Router behaviour is assumed.
+ If local forwarding is enabled, Router behaviour is assumed.
This means exactly the reverse from the above:
1. IsRouter flag is set in Neighbour Advertisements.
Default: 4
router_solicitations - INTEGER
- Number of Router Solicitations to send until assuming no
+ Number of Router Solicitations to send until assuming no
routers are present.
Default: 3
max_desync_factor - INTEGER
Maximum value for DESYNC_FACTOR, which is a random value
- that ensures that clients don't synchronize with each
+ that ensures that clients don't synchronize with each
other and generate new addresses at exactly the same time.
value is in seconds.
Default: 600
-
+
regen_max_retry - INTEGER
Number of attempts before give up attempting to generate
valid temporary addresses.
max_addresses - INTEGER
Number of maximum addresses per interface. 0 disables limitation.
- It is recommended not set too large value (or 0) because it would
- be too easy way to crash kernel to allow to create too much of
+ It is recommended not set too large value (or 0) because it would
+ be too easy way to crash kernel to allow to create too much of
autoconfigured addresses.
Default: 16
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff