Warning: date(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected the timezone 'UTC' for now, but please set date.timezone to select your timezone. in /usr/home/webadmin/www/sysctl/class.rss.php on line 40
Warning: Cannot modify header information - headers already sent by (output started at /usr/home/webadmin/www/sysctl/class.rss.php:40) in /usr/home/webadmin/www/sysctl/class.rss.php on line 59 EnderUnix Sysctl
http://sysctl.enderunix.org/
EnderUnix Sysctl SitesitrMon, 18 Jan 2021 14:42:24 +0000EnderUNIX Free Software Development TeamEnable non-privileged users to mount filesystems
http://sysctl.enderunix.org/view.php?id=258
# sysctl vfs.usermount=1
This command enables non-privileged users to mount filesystems.2008-04-07 10:42:50Normal Kullanicilara mount Izni Vermek
http://sysctl.enderunix.org/view.php?id=257
# sysctl vfs.usermount=1
komutu ile root hakki olmayan kullanicilarin dosya sistemi mount etmesine izin verilir.2008-04-07 10:41:08net.inet.ip.ttl
http://sysctl.enderunix.org/view.php?id=252
The default is the value of the system\#039;s net.inet.ip.ttl MIB variable, which defaults to 64.
OpenBSD man 8 traceroute2007-12-18 09:17:40check your maximum filedescriptors
http://sysctl.enderunix.org/view.php?id=245
You can check your maximum filedescriptors as follow below
# sysctl -a | grep #039;kern.maxfile#039;
You can increase them as follow below
# sysctl -w kern.maxfiles=XXXX
# sysctl -w kern.maxfilesperproc=XXXX
2007-06-16 00:26:15Maksimum dosyatanimlayici sayisini ouml;eth;renmek
http://sysctl.enderunix.org/view.php?id=244
Maksimum dosyatanimlayici sayisini ogrenebilmek icin
# sysctl -a | grep #039;kern.maxfile#039;
Dosyatanimlayici sayisini artirmak icin ise
# sysctl -w kern.maxfiles=XXXX
# sysctl -w kern.maxfilesperproc=XXXX
2007-06-16 00:25:22net.ipv4.igmp_max_memberships
http://sysctl.enderunix.org/view.php?id=238
Host üzerinde dinlenebilecek maximum igmp socket sayısı (multicast grubuna dahil olacak hostların sayısı da denebilir)2007-01-30 16:18:52net.ipv4.igmp_max_memberships
http://sysctl.enderunix.org/view.php?id=237
Maximum number of listening igmp (multicast) sockets on the host2007-01-30 16:08:37kern.ipc.msgtql
http://sysctl.enderunix.org/view.php?id=235
Maximum number of messages in the system2007-01-17 02:06:26kern.ipc.msgmax
http://sysctl.enderunix.org/view.php?id=234
Maximum message size within the system2007-01-17 02:05:30kern.ipc.msgmni
http://sysctl.enderunix.org/view.php?id=233
Number of message queue identifiers present in the system2007-01-17 02:04:26kern.ipc.msgmnb
http://sysctl.enderunix.org/view.php?id=232
Maximum number of bytes in a queue2007-01-16 23:46:14kern.ipc.msgseg
http://sysctl.enderunix.org/view.php?id=231
Number of message segments within a particular message queue.2007-01-16 23:37:23hw.ata.wc
http://sysctl.enderunix.org/view.php?id=230
hw.ata.wc değri 1 yapılarak ATA disklerde yazılacak bilgilerin öncelikle önbellekte saklanması sağlanır. Ancak bu durumda sistemin aniden kapanması sonucu kaybedilecek canlı veri miktarı daha fazla olacaktır.2006-12-13 22:01:38net.bpf.maxbufsize
http://sysctl.enderunix.org/view.php?id=223
Specifies the upper limit which can be set for net.bpf.bufsize.
See also:
http://sysctl.enderunix.org/view.php?id=222amp;lang=en
Default value: 5242882006-11-02 21:42:22net.bpf.bufsize
http://sysctl.enderunix.org/view.php?id=222
Berkeley Packet Filter (BPF), maintains an internal kernel buffer for storing packets received off the wire. This knob controls the size (in bytes) of that buffer.
Default value: 4096 bytes.
Please be noted that, there is an upper limit set by another BPF sysctl (net.bpf.maxbufsize). If you need much larger buffer space, you need to increase that one also.
2006-11-02 21:22:20net.inet.tcp.sendspace
http://sysctl.enderunix.org/view.php?id=159
TCP protokolünde paket gönderimini kapsayan
basit ince bir detay;
# sysctl net.inet.tcp.sendspace=65536
(Default seçenekler de bu değer 32768dir.)
Yapılan değişikliği kontrol etmek için
# sysctl -a | grep sendspace
komutunu kullanabilirsiniz.Eğer sistemimiz her
açılışta bu değerle başlamasını istiyorsak
önümüzde 2 değişik seçenek var.
1. Sysctl.conf dosyasına ekleyebil2006-01-03 17:03:07hw.clockrate
http://sysctl.enderunix.org/view.php?id=142
determine the cpu frequency2005-12-01 15:45:01net.inet.tcp.rexmit_min
http://sysctl.enderunix.org/view.php?id=141
Minimum Retransmission Timeout
root@siseci[~]# sysctl net.inet.tcp.rexmit_min
net.inet.tcp.rexmit_min: 30
2005-11-30 08:47:46net.inet.tcp.msl
http://sysctl.enderunix.org/view.php?id=140
Maximum segment lifetime
root@siseci[~]# sysctl net.inet.tcp.msl
net.inet.tcp.msl: 30000
2005-11-30 08:47:07net.inet.tcp.delayed_ack
http://sysctl.enderunix.org/view.php?id=139
Delay ACK to try and piggyback it onto a data packet
root@siseci[~]# sysctl net.inet.tcp.delayed_ack
net.inet.tcp.delayed_ack: 1
2005-11-30 08:44:17net.inet.tcp.delacktime
http://sysctl.enderunix.org/view.php?id=138
Time before a delayed ACK is sent
root@siseci[~]# sysctl net.inet.tcp.delacktime
net.inet.tcp.delacktime: 100
2005-11-30 08:43:17net.inet.tcp.stats
http://sysctl.enderunix.org/view.php?id=137
TCP statistics (struct tcpstat, netinet/tcp_var.h)
2005-11-30 08:41:01net.inet.tcp.mssdflt
http://sysctl.enderunix.org/view.php?id=136
Default TCP Maximum Segment Size2005-11-30 08:40:40net.inet.tcp.rfc1644
http://sysctl.enderunix.org/view.php?id=135
Enable rfc1644 (TTCP) extensions
http://rfc.net/rfc1644.html2005-11-30 08:40:18vfs.generic.usermount
http://sysctl.enderunix.org/view.php?id=133
In NetBSD, a file system can only be mounted by an ordinary user who owns the point node and has access to the special device (at least read permissions). In addition, the vfs.generic.usermount sysctl must be set to 1 to permit file system mounting by ordinary users.
mount(8)2005-11-24 23:15:45net.inet.tcp.mss_ifmtu
http://sysctl.enderunix.org/view.php?id=132
Some systems behind misconfigured firewalls try to use Path-MTU-Discovery, while their firewall blocks all ICMP messages. This is an illegal, but not uncommon, setup. Typically you will have no chance to fix this (remote, outside of your control) setup. And sometimes you will have to use such remote systems (to download data from them, or to do your online banking).
Without special care systems2005-11-24 21:20:20hw.ncpu
http://sysctl.enderunix.org/view.php?id=131
Sistemdeki islemci sayisini gosterir.
root@siseci# sysctl hw.ncpu
hw.ncpu: 4
2005-11-16 10:36:17net.inet.tcp.sendspace
http://sysctl.enderunix.org/view.php?id=118
TCP Send window size.2005-10-14 14:35:10net.inet.tcp.recvspace
http://sysctl.enderunix.org/view.php?id=117
TCP receive window size.2005-10-14 14:26:57net.inet.ip.sourceroute
http://sysctl.enderunix.org/view.php?id=115
To disable IP source routing set
net.inet.ip.sourceroute
and
net.inet.ip.accept_sourceroute
to 0.
2005-10-14 14:22:25net.inet.icmp.masqrepl
http://sysctl.enderunix.org/view.php?id=113
Disable ICMP router solicitations and advertisements, and ICMP subnet mask requests and replies.2005-10-14 14:18:14net.link.ether.inet.max_age
http://sysctl.enderunix.org/view.php?id=112
ARP onbelleginin temizlenme suresidir.
Ontanimli degeri 1200 dur.
2005-10-14 14:14:45kern.ident
http://sysctl.enderunix.org/view.php?id=111
Kernel configurasyon dosyasinda gecen ident satiridir.
ident GENERIC
Satiri degistirilerek degistirilebilir.2005-10-14 09:54:41kern.securelevel
http://sysctl.enderunix.org/view.php?id=109
A MIB to set system security level.
The kernel runs with five different levels of security. Any super-user
process can raise the security level, but no process can lower it. The
security levels are:
-1 Permanently insecure mode - always run the system in level 0 mode.
This is the default initial value.
0 Insecure mode - immutable and append-only flags may 2005-08-23 14:45:17kern.logsigexit
http://sysctl.enderunix.org/view.php?id=108
Log processes quitting on abnormal signals (e.g. sig 11) to syslog(3)
2005-08-23 13:47:08kern.fast_vfork
http://sysctl.enderunix.org/view.php?id=107
Enable fast vfork() by using RFMEM to share address space instead of copying it2005-08-23 13:36:38net.inet.udp.log_in_vai
http://sysctl.enderunix.org/view.php?id=106
Enables logging of attempted connections to ports which do not have a server running. The dmesg will display the attempt and it it will be logged to /var/log/messages.
For all udp datagrams, to ports on which there is no socket listening, log the connection attempt.
There is also a net.inet.tcp.log_in_vain.2005-07-23 23:50:05net.inet.tcp.inflight
http://sysctl.enderunix.org/view.php?id=105
[inflight.enable]
-
Enable TCP bandwidth-delay product limiting. An
attempt will be made to calculate the bandwidth-delay
product for each individual TCP connection, and limit
the amount of inflight data being transmitted, to
avoid building up unnecessary packets in the network.
This option is re2005-07-23 23:44:07net.inet.tcp.syncache
http://sysctl.enderunix.org/view.php?id=104
The syncache implements a number of variables in the
net.inet.tcp.syncache branch of the sysctl(3) MIB. Several of these may be tuned by setting the corresponding variable in the loader(8).
[hashsize] - Size of the syncache hash table, must be a power of 2.
Read-only, tunable via loader(8).
[bucketlimit] - Limit on the number of entries permitted in each bucket of the hash ta2005-07-23 23:36:27net.inet.tcp.syncookies
http://sysctl.enderunix.org/view.php?id=103
Determines whether or not SYN cookies should be generated for outbound SYN-ACK packets. SYN cookies are a great help during SYN flood attacks, and are enabled by default. (See syncookies(4).)
2005-07-23 23:31:20net.inet.tcp.do_tcpdrain
http://sysctl.enderunix.org/view.php?id=102
Flush packets in the TCP reassembly queue if the system is low on mbufs.
2005-07-23 23:29:33net.inet.tcp.always_keepalive
http://sysctl.enderunix.org/view.php?id=101
Assume that SO_KEEPALIVE is set on all TCP connections, the kernel will periodically send a packet to the remote host to verify the connection is still up.
2005-07-23 23:28:18net.inet.tcp.keepinit
http://sysctl.enderunix.org/view.php?id=100
Timeout, in milliseconds, for new, non-established TCP connections.
2005-07-23 23:27:14net.inet.tcp.keepintvl
http://sysctl.enderunix.org/view.php?id=99
The interval, in milliseconds, between keepalive probes sent to remote machines. After TCPTV_KEEPCNT (default 8) probes are sent, with no response, the (tcp)connection is dropped.2005-07-23 23:26:09net.inet.tcp.keepidle
http://sysctl.enderunix.org/view.php?id=98
Amount of time, in milliseconds, that the (tcp) connection must be idle before keepalive probes (if enabled) are sent.
2005-07-23 23:24:54kern.random.sys.harvest.interrupt
http://sysctl.enderunix.org/view.php?id=97
The kern.random.sys.harvest.interrupt variable is used to select hardware interrupts as an entropy source. A 0 (zero) value means interrupts are not considered as an entropy source. Set the variable to 1 (one) if you wish to use them for entropy harvesting. All interrupt harvesting is setup by the individual device drivers.
2005-07-23 23:21:43kern.random.sys.harvest.point_to_point
http://sysctl.enderunix.org/view.php?id=96
The kern.random.sys.harvest.point_to_point variable is used to select serial line traffic as an entropy source. (Serial line traffic includes PPP, SLIP and all tun0 traffic.) A 0 (zero) value means such traffic is not considered as an entropy source. Set the variable to 1 (one) if you wish to use it for entropy harvesting.2005-07-23 23:20:53kern.random.sys.harvest.ethernet
http://sysctl.enderunix.org/view.php?id=95
The kern.random.sys.harvest.ethernet variable is used to select LAN traffic as an entropy source. A 0 (zero) value means that LAN traffic is not considered as an entropy source. Set the variable to 1 (one) if you wish to use LAN traffic for entropy harvesting.2005-07-23 23:19:34kern.random.sys.burst
http://sysctl.enderunix.org/view.php?id=94
The kern.random.sys.burst variable instructs the kernel thread that processes the harvest queue to tsleep(9) briefly after that many events have been processed. This helps prevent the random device from being so compute-bound that it takes over all processing ability. A value of 0 (zero) is treated as infinity, and will only allow the kernel to pause if the queue is empty. Only values in the ra2005-07-23 23:18:42kern.random.sys.seeded
http://sysctl.enderunix.org/view.php?id=93
The kern.random.sys.seeded variable indicates whether or not the random device is in an acceptably secure state as a result of reseeding. If set to 0, the device will block (on read) until the next reseed (which can be from an explicit write, or as a result of entropy harvesting). A reseed will set the value to 1 (non-blocking).2005-07-23 23:17:31net.inet.udp.blackhole
http://sysctl.enderunix.org/view.php?id=92
From the blackhole(4) manual page:
The blackhole sysctl(8) MIB is used to control
system behaviour when connection requests are
received on TCP or UDP ports where there is no
socket listening.
Normal behaviour, when a TCP SYN segment is
received on a port where there is no socket
accepting connections, is for the system to
return a RST segment, and drop the connection.
The connecting 2005-07-23 23:13:58kern.domainname
http://sysctl.enderunix.org/view.php?id=91
current domainname of the operating system (domainname)2005-07-23 23:11:04kern.hostname
http://sysctl.enderunix.org/view.php?id=90
current hostname of the operating system (hostname -s)2005-07-23 23:10:03kern.osrelease
http://sysctl.enderunix.org/view.php?id=89
current release level of the operating system (uname -r)2005-07-23 23:06:31vm.stats
http://sysctl.enderunix.org/view.php?id=88
sysctl vm.stats will show you all the memory info you need in the vm system, as in: pageable memory. Its shown in number of pages (usually 4K: vm.stats.vm.v_page_size).
2005-07-20 14:02:55hw.physmem
http://sysctl.enderunix.org/view.php?id=87
Bilgisayarinizin fiziksel ramini byte cinsinden gosterir
Örnegin;
# sysctl hw.physmem
hw.physmem: 263688192
2005-07-20 12:06:40Ses kartlarında çoklu sanal kanal açmak
http://sysctl.enderunix.org/view.php?id=86
Gelişmiş tüm ses kartlarında bulunan çoklu sanal kanal özelliğini freebsd altında kullanmak için;
sysctl hw.snd.maxautovchans=4
komutunu vermeniz yeterli.
Bu sayede aynı anda birden fazla ses kaynağını dinleyebilirsiniz.2005-07-06 15:31:25 vfs.vmiodirenable
http://sysctl.enderunix.org/view.php?id=85
This ysctl variable may be set to either 0 (off) or 1 (on); it is 1 by default.
This variable controls how directories are cached by the system.
It improves performance on servers with lots of i/o files such as mail servers, web caches and databases.
Ref: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/book.html#AEN16786
2005-07-04 15:42:26hw.ata.wc
http://sysctl.enderunix.org/view.php?id=84
hw.ata.wc: (0/1) enable(1) / disable (0) ATA disk write caching.2005-07-04 15:37:42hw.model
http://sysctl.enderunix.org/view.php?id=83
hw.model: specific machine model
hw.model: Intel(R) Pentium(R) 4 CPU 1.80GHz
2005-07-04 15:25:22hw.pagesize
http://sysctl.enderunix.org/view.php?id=82
hw.pagesize: System memory page size.
2005-07-04 15:24:11hw.ncpu
http://sysctl.enderunix.org/view.php?id=81
hw.ncpu:number of cpus
2005-07-04 15:17:11hw.physmem
http://sysctl.enderunix.org/view.php?id=80
hw.physmem is a physical memory size in bytes.
hw.physmem: 782921728
2005-07-04 15:14:29dev.cpu.0.freq_levels
http://sysctl.enderunix.org/view.php?id=79
displays supported cpu states for your cpu (for processors that support this)
to set a desired frequency, use
dev.cpu.0.freq=x2005-06-10 00:44:03net.inet.tcp.rfc1323
http://sysctl.enderunix.org/view.php?id=78
net.inet.tcp.rfc1323: Enable rfc1323 (high performance TCP) extensions.
http://rfc.net/rfc1323.html2005-06-09 16:02:12net.inet.ip.check_interface
http://sysctl.enderunix.org/view.php?id=77
inet.ip.check_interface: Verify packet arrives on correct interface
ip_checkinterface currently must be disabled if you use ipnat 150 to translate the destination address to another local interface.
Also it must be disabled if you add IP aliases to the loopback interface instead of the interface where the packets for those addresses are received.
2005-06-09 15:57:31kern.rootdev
http://sysctl.enderunix.org/view.php?id=76
kern.rootdev: root device of the system.
# sysctl kern.rootdev
kern.rootdev: da0s1a
2005-06-09 13:06:43kern.openfiles - 2
http://sysctl.enderunix.org/view.php?id=75
kern.openfiles: System-wide number of open files.
2005-06-09 13:01:03kern.disks
http://sysctl.enderunix.org/view.php?id=74
kern.disks gets a list of all disks in the system.
Output:
# sysctl kern.disks
kern.disks: ad0 md0
2005-06-09 12:58:13net.inet.icmp.icmplim_output
http://sysctl.enderunix.org/view.php?id=73
net.inet.icmp.icmplim_output: If (0) you do not want to see messages about this in your log files, but you still want the kernel to do response limiting.
2005-06-06 17:50:09net.inet.icmp.icmplim
http://sysctl.enderunix.org/view.php?id=72
net.inet.icmp.icmplim: the maximum number of ICMP Unreachable and also TCP RST packets that will be sent back every second.2005-06-06 17:48:02vfs.ufs
http://sysctl.enderunix.org/view.php?id=71
vfs.ufs.dirhash_minsize: minimum directory size in bytes for which to use hashed lookup
vfs.ufs.dirhash_maxmem: maximum allowed dirhash memory usage
vfs.ufs.dirhash_mem:current dirhash memory usage
vfs.ufs.dirhash_docheck:enable extra sanity tests
2005-06-06 17:29:19kern.nodump_coredump
http://sysctl.enderunix.org/view.php?id=70
kern.nodump_coredump:Enable setting the NODUMP flag on coredump files
Default value:
kern.nodump_coredump: 0
2005-06-06 16:58:35kern.coredump
http://sysctl.enderunix.org/view.php?id=69
kern.coredump:Enable/Disable coredumps
Default value:
kern.coredump: 1
2005-06-06 16:57:12kern.sugid_coredump
http://sysctl.enderunix.org/view.php?id=68
kern.sugid_coredump: Enable coredumping set user/group ID processes
Default value:
kern.sugid_coredump: 0
2005-06-06 16:55:59kern.corefile
http://sysctl.enderunix.org/view.php?id=67
kern.corefile: core file name format string.
Default value:
kern.corefile: %N.core2005-06-06 16:54:09kern.smp
http://sysctl.enderunix.org/view.php?id=66
kern.smp.maxcpus: Max number of CPUs that the system was compiled for
kern.smp.active:are the APs allowed to run?
kern.smp.disabled: has smp been disabled?
kern.smp.cpus: Number of CPUs online.
kern.smp.forward_signal_enabled: Enable forwarding of a signal to a process running on a different CPU
kern.smp.forward_roundrobin_enabled:Enable forwarding of roundrobin to all other cpus
2005-06-06 16:43:01kern.maxprocperuid
http://sysctl.enderunix.org/view.php?id=65
The maximum number of the processes for per user id.
kern.maxprocperuid is changeable.2005-06-05 13:51:35kern.maxproc
http://sysctl.enderunix.org/view.php?id=64
The maximum number of processes a user may be running.
kern.maxproc is read only
2005-06-05 13:43:28kern.boottime
http://sysctl.enderunix.org/view.php?id=63
the boot time of the kernel.2005-06-05 13:38:05kern.maxvnodes
http://sysctl.enderunix.org/view.php?id=62
A vnode is the internal representation of a file or directory. So increasing the number of vnodes available to the operating system cuts down on disk I/O
kern.maxvnodes is changeable2005-06-05 13:33:27kern.ostype
http://sysctl.enderunix.org/view.php?id=61
contains the type of the kernel.2005-06-05 13:31:42net.link.ether.inet.max_age
http://sysctl.enderunix.org/view.php?id=60
The cleanup interval for the IP route cache.
Default value: 1200
2005-06-05 01:18:21hw.tweX.driver_version
http://sysctl.enderunix.org/view.php?id=58
Gives the version of the twe driver.2005-05-27 21:17:02fs.file-max
http://sysctl.enderunix.org/view.php?id=57
Bu parametre linux sisteminde açılabilecek dosya handle larının(bu da açılabilecek maksimum dosya sayisini gosterir) maksimum sayisini verir2005-05-24 19:08:43kernel.sem
http://sysctl.enderunix.org/view.php?id=56
SEMMSL,SEMMNS, SEMOPM, SEMMNI parametrelerini içerir(örnek : 250 32000 32 128).
SEMMSL : Bir semafor setinin içindeki maksimum semafor sayisini verir
SEMMNS : Linux sistemimizdeki toplam semafor sayisini verir
SEMOPM : Bu parametre semop(2) sistem çağrısının bir seferde yapabilecegi maksimum semafor operasyonlarinin sayisini verir
SEMMNI : Linux sistemimizdeki maksimum semafor seti 2005-05-24 19:06:01kernel.shmall
http://sysctl.enderunix.org/view.php?id=55
Sistemde bir anda sayfalarda(page) kullanılabilecek toplam paylasimli hafiza(shared memory) miktarini verir ve en az ceil(SHMMAX/PAGE_SIZE) kadar olmalidir2005-05-24 18:57:15kernel.shmmni
http://sysctl.enderunix.org/view.php?id=54
Sistem genelindeki maksşmum paylasimli hafiza segment(shared memory segment) saysini belirler2005-05-24 18:39:27kernel.shmmax
http://sysctl.enderunix.org/view.php?id=53
Paylaşılan bellek segmentinin(shared memory segment) byte cinsinden maksimum değeridir2005-05-24 18:37:45kern.openfiles
http://sysctl.enderunix.org/view.php?id=52
Shows current number of open files.2005-05-18 05:29:05hw.snd.maxautovchans
http://sysctl.enderunix.org/view.php?id=51
hw.snd.maxautovchans=X
where X is the number of virtual channels a new audio device is given when it is attached using kldload2005-05-15 22:53:46hw.snd.pcm0.vchans
http://sysctl.enderunix.org/view.php?id=50
hw.snd.pcm0.vchans=X
where X is the number of virtual channels pcm0 has2005-05-15 22:52:20kern.maxfiles
http://sysctl.enderunix.org/view.php?id=49
This variable indicates the maximum number of file descriptors on your system.
2005-05-15 20:57:18net.link.ether.inet.log_arp_movements
http://sysctl.enderunix.org/view.php?id=48
Boolean MIB
The default is 0 (OFF)
By setting this knob to 1 (ON) the kernel will log all ARP broadcasts from hosts that have a MAC address that is different then the on in the ARP cache on the localhost.
This might help preventing and identifying ARP cache poisoning attacks.2005-05-15 20:37:55net.link.ether.inet.log_arp_wrong_iface
http://sysctl.enderunix.org/view.php?id=47
Boolean MIB
The default is 0 (OFF)
By setting this knob to 1 (ON) the kernel will log all arp packets arriving on the wrong interface.
2005-05-15 20:34:08net.inet.ip.random_id
http://sysctl.enderunix.org/view.php?id=46
Boolean MIB
0 - off
1 - on
The default is OFF (0).
Normally (when this option is OFF) IP_ID of IP packets are numbered in an sequential manner. By setting this knob to 1 (ON) the IP_ID is set with a random number. This can help in preventing an information-gathering attack i.e. when an attacker
tracks diffrent IP_IDs leaving a router to find how many hosts are behind the NAT.2005-05-15 20:30:55net.link.ether.ipfw
http://sysctl.enderunix.org/view.php?id=45
FreeBSD 4.x lerde çekirdeğinizde options IPFW2 varsa
FreeBSD 5.x lerde çekirdeğinizde options IPFIREWALL varsa
net.link.ether.ipfw=1
ile MAC adresine gore (Layer2) filtreleme yapabilirsiniz
net.link.ether.ipfw=0
ise Layer2 filtrelemeyi iptal eder. (Standartta bu seçilidir)2005-05-13 23:57:34net.link.ether.bridge_ipfw
http://sysctl.enderunix.org/view.php?id=44
Çekirdeğinizi options IPFIREWALL ve options BRIDGE ile derlemişseniz;
net.link.ether.bridge_ipfw=1
ile bridge paketlerini firewalldan gecirirsiniz.
net.link.ether.bridge_ipfw=0
ise bridge paketleri firewalla ugramadan gecer.2005-05-13 23:55:14net.inet.tcp.log_in_vain
http://sysctl.enderunix.org/view.php?id=43
Uzerinde sunucu servis calismaya port`lara baglanti yapilmaya calisildiginda bunu gunluk dosyasina atmak icin kullanilabilir.dmesg bu baglantiyi gosterirken ayrica bu mesaj /var/log/messages altina yazilacaktir.
Sadece SYN bayragi olan TCP paketlerinin kaydi tutulacaktir.Bunun yaninda ayrica net.inet.udp.log_in_vain bulunmaktadir.
2005-05-09 17:48:05net.inet.tcp.icmp_may_rst - 2
http://sysctl.enderunix.org/view.php?id=42
Belli bir ICMP mesaji aldiginda TCP`nin bir baglantiyi kesebilmesine olanak verir.
(bakiniz: RFC 1122, 4.2.3.9, Destination unreachable 2-4).
Baglanti TCP durumu ancak SYN_SENT ise iptal edilebilir.
2005-05-09 17:45:25