After a deep review of network and CIDR notation I often see in linux config file:
127.0.0.1/8
to set network loopback interface.
The correct CIDR should be
127.0.0.0/8
Because 127.0.0.1 is the loopback IP. Why many default linux and bsd config file use the first?
I created new files in
/etc/logrotate.d/
how run an iteration of logrotate manually to check these?
I have 2 wireless bridges connected to DSL. I'd like see the path of my connection from my pc to internet.
traceroute works at layer 3, bridges works at layer 2. Is there a command like traceroute that works at layer2?
Using these ps options I cut 10 lines and order output of ps by cpu usage (pcpu):
ps -eo pcpu,etime,pid,user,args --no-headers| sort -t. -nk1,2 -k4,4 -r |head -n 10
I need also show the name of columns (like same commands without cutting the output).
%CPU ELAPSED PID USER COMMAND
0.0 10-23:41:11 1 root init [2]
0.0 10-23:41:11 2 root [kthreadd]
unfortunately I don't have access to ssh server, I can only see:
Platform: i586-pc-linux-gnu
Compiled with: liblua-5.2.3 openssl-1.0.1k libpcre-8.35 libpcap-1.6.2 nmap-libdnet-1.12 ipv6
Compiled without:
Available nsock engines: epoll poll select
ssh -vvvl user ip
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_setup: setup hmac-sha1
debug1: kex: server->client 3des-cbc hmac-sha1 none
debug2: mac_setup: setup hmac-sha1
debug1: kex: client->server 3des-cbc hmac-sha1 none
debug2: bits set: 502/1024
debug1: sending SSH2_MSG_KEXDH_INIT
debug1: expecting SSH2_MSG_KEXDH_REPLY
Connection closed by IP
Considering a standard LAMP server (aka webhosting) what should be a limit at number of processes/thread?
ps -elfT | wc -l
475
"Limit" I mean: on DDOS probably the numbers of children-processes of httpd will increase quickly.
Review linux load average documentation (to try to solve a problem) I'm ask if a kind of state of process (zombie process?) can affect to anomaly that causes an high load average of my system. So, zombie processes can have negative effects to my problem? Are there other kind of state of process that increase load average?
on centos 6 I need take the values from a dhcp server:
cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
HWADDR=00:50:56:27:0E:C8
TYPE=Ethernet
UUID=20924b21-e92a-4944-a054-06d1967155c1
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=dhcp
PEERDNS=yes
dhclient take only IP (not gw, not dns, not hostname).
There is not any dhclient.conf not even an example file.
Sometimes I dive into my network and often I see:
tcpdump -n arp
17:59:15.754508 ARP, Request who-has 192.168.1.65 tell 192.168.1.212, length 28
17:59:16.754401 ARP, Request who-has 192.168.1.65 tell 192.168.1.212, length 28
17:59:17.754449 ARP, Request who-has 192.168.1.65 tell 192.168.1.212, length 28
17:59:18.754505 ARP, Request who-has 192.168.1.65 tell 192.168.1.212, length 28
17:59:19.754435 ARP, Request who-has 192.168.1.65 tell 192.168.1.212, length 28
17:59:20.754422 ARP, Request who-has 192.168.1.65 tell 192.168.1.212, length 28
192.168.1.212 is a primary linux server:
ip addr
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether c0:4a:00:02:78:c5 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.212/24 brd 192.168.1.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::c24a:ff:fe02:78c5/64 scope link
valid_lft forever preferred_lft forever
does this behavior a problem or warning or what? 192.168.1.65 is a windows client emulated (often turned off).
After installed WSUS on win server 2008, I need to create a script (to execute) on windows clients to automatically modify some settings, ie:
Group Policy Object Editor -> Computer Configuration -> Administrative Templates -> Windows Components -> Windows Update
is there a comfortable way?
I've a postfix server to deliver local emails using Maildir format. Inside home users I've
cat /home/$USER/.muttrc
set from="[email protected]"
set realname="user1"
set mbox_type=Maildir
set folder="~/Maildir"
set mask="!^\\.[^.]"
set mbox="~/Maildir"
set record="+.Sent"
set postponed="+.Drafts"
set spoolfile="~/Maildir"
set timeout=30
does mutt support notification via shell of new email? Like: "You have X new mails". Because does not run.
I'd like to customize an alert message for the following condition:
if cpu > 75% for 2 cycles then exec "command|mail -s subject [email protected]"
to monitrc config file
how can I add that command?
check process apache with pidfile /var/run/apache2.pid
start program = "/etc/init.d/apache2 start" with timeout 60 seconds
stop program = "/etc/init.d/apache2 stop"
if cpu > 60% for 2 cycles then alert
if cpu > 80% for 5 cycles then restart # 10minutes
if totalmem > 200.0 MB for 5 cycles then restart
if children > 250 then restart
if loadavg(5min) greater than 10 for 8 cycles then stop
if failed host 192.168.1.200 port 80 protocol http
and request "/monit/token"
then restart
Why if I add that line no email is sent when condition is met? Any ideas?