Table des matières
- 2026:
- 2025:
4 billet(s) pour septembre 2026
| Notes HTTP Strict Transport Security - HSTS | 2026/09/18 11:04 | Jean-Baptiste |
| Notes GNU Linux GPU carte graphiques | 2026/09/08 15:49 | Jean-Baptiste |
| Notes GNU Linux graphique | 2026/09/08 15:42 | Jean-Baptiste |
| Notes urlencoding - passer des mots de passe en HTTPS | 2026/09/03 17:58 | Jean-Baptiste |
Notes iTop ITSM ESM CMDB ITIL
Voir :
Voir aussi :
-
- i-doit - Web based IT documentation and Configuration Management Database
- Ralph - lightweight asset management system
- Zenoss Core / Zenoss Community Edition: AIOps. Full-Stack Monitoring. Observability.
- CMDBuild
- GLPI / FusionInventory
sudo docker run -d -p 8000:80 --name=my-itop vbkunin/itop
Notes IPVS
Brouillon
Voir :
Voir aussi
Notes IPv6
Voir :
- RFC 2373 (IPv6 address in colon and dot notation)
Notes iptables
Note : iptables est remplacé maintenant par nftables
Voir :
Voir les règles
iptables -L -n -v
ou
iptables -S
Les bases
Il existe les tables :
- filter (défaut)
- nat
- mangle
Bloquer une IP en sortie
Pour bloquer l'IP 192.168.2.18 en sortie.
iptables -I OUTPUT -d 192.168.2.18 -j REJECT
Pour effacer la règle
iptables -D OUTPUT -d 192.168.2.18 -j REJECT
Nettoyer / supprimer plusieurs règles qui contiennent un motif spécifique
Exemple : pour supprimer toutes les règles contenant “445”
iptables -S | grep 445 | sed -e 's/^-A/-D/' | xargs -L1 iptables
Logs
iptables -A INPUT -p igmp -j LOG --log-level info --log-prefix "IGMP:" # log pour paquets refusés iptables -N LOGDROP iptables -A LOGDROP -m limit --limit 5/second -j LOG --log-level notice --log-ip-options --log-prefix "Netfilter refused:" iptables -A LOGDROP -j DROP # iptables -A pub-priv -m limit --limit 5/second -j LOG --log-level notice --log-ip-options --log-prefix "Netfilter pub-priv:" iptables -A FORWARD -j LOGDROP iptables -A INPUT -j LOGDROP iptables -A INPUT -p icmp -m limit -j LOG --log-prefix "ICMP/IN: " iptables -A OUTPUT -p icmp -m limit -j LOG --log-prefix "ICMP/OUT: " iptables -A FORWARD -p icmp -m limit -j LOG --log-prefix "ICMP/FWD: "
Notes IPC shared memory
Voir :
- https://www.youtube.com/watch?v=9OZofG500Js Processus et Sémaphores Chaker El Amrani
ipcrm/ipcmk
Voir aussi :
#Total de la RAM total=$(cat /proc/meminfo | grep MemTotal | awk '{print $2}') # 90% de la mémoire physique max ratio=0.9 # On applique le ratio et on converti en pages de 4096 shmall=$(echo $total/4096*$ratio+1 | bc) shmmax=$(echo $total*$ratio | bc) # On arrondi la valeur shmall=$(echo $shmall | sed -e 's/\..*$//') shmmax=$(echo $shmmax | sed -e 's/\..*$//') echo $shmall > /proc/sys/kernel/shmall echo $shmmax > /proc/sys/kernel/shmmax # ipcs -lm ################# ################# # Overcommit memory ? # sysctl -w vm.overcommit_memory=2 # Page size ? # getconf PAGE_SIZE # cat /proc/sys/kernel/shmmni ################# #### SEMAPHORES # http://www.postgresql.org/docs/9.1/static/runtime-config-connection.html#GUC-MAX-CONNECTIONS # SEMMNS is the second parameter in output of cat /proc/sys/kernel/sem (default value 32000) # SEMMNI is the last parameter there, default value 128 - this is the limiting factor - SEMMNI must be at least at least ceil(max_connections / 16) # http://www.puschitz.com/TuningLinuxForOracle.shtml#TheSEMMNSParameter # http://www.postgresql.org.es/node/229 ####
Connaître la PAGE_SIZE \ Voir https://en.wikipedia.org/wiki/Page_%28computer_memory%29
getconf PAGE_SIZE cat /proc/sys/kernel/shmmni
$ ipcs ------ Message Queues -------- key msqid owner perms used-bytes messages ------ Shared Memory Segments -------- key shmid owner perms bytes nattch status 0x0052e2c1 32768 postgres 600 56 20 0x00000000 17924097 wouter 600 33554432 2 dest 0x00000000 49446914 wouter 600 524288 2 dest [...] $ ipcs -i 17924097 -m -p Shared memory Segment shmid=17924097 uid=1000 gid=1000 cuid=1000 cgid=1000 mode=01600 access_perms=0600 bytes=33554432 lpid=3808 cpid=1457 nattch=2 att_time=Fri Jul 3 10:43:28 2015 det_time=Fri Jul 3 10:43:28 2015 change_time=Fri Jul 3 10:03:00 2015
Debug
Source : http://www.makelinux.net/alp/035
The ipcs command provides information on interprocess communication facilities, including shared segments. Use the -m flag to obtain information about shared memory. For example, this code illustrates that one shared memory segment, numbered 1627649, is in use:
$ ipcs -m ------ Shared Memory Segments ------- key shmid owner perms bytes nattch status 0x00000000 1627649 user 640 25600 0
If this memory segment was erroneously left behind by a program, you can use the ipcrm command to remove it.
ipcrm shm 1627649
Periodically remove allocated semaphores which belong to the user running the plugin. This can be achieved like this (example for the user “nrpe”)\ Source : http://folk.uio.no/trondham/software/check_openmanage.html
ipcrm $(ipcs -s | awk '/nrpe/ {print "-s ",$2}')