29 Feb 2008 Configure squid to ignore some sites
If you are using squid like me, it is sometimes useful to avoid cacheing some internet addresses. To accomplish this you could edit your /etc/squid/squid.conf file and add the following line
acl NOCACHEDOMAIN dstdomain www.vg.no no_cache deny NOCACHEDOMAIN
This makes it possible to view www.vg.no without viewing a squid cached page.
Tags: squid
Posted by Hans-Henry Jakobsen
27 Feb 2008 rpcbind and auth ports open
The last time I installed Debian Etch i closed both port 111 and 113 but since I’ve forgot it already and a new installation is in progress, this post should remind me how to do it in the future. The code view below shows the ports nmap found were in a open state
PORT STATE SERVICE 111/tcp open rpcbind 113/tcp open auth
Port 113/auth can be closed by commenting out the ident line in the /etc/inetd.conf
#ident stream tcp wait identd /usr/sbin/identd identd
Port 111 is the portmap daemon and can be configured to only listen on the loopback interface
dpkg-reconfigure portmap
This command modifies the /etc/default/portmap file and adds/uncomments the line
OPTIONS="-i 127.0.0.1"
Tags: auth, Debian, dpkg-reconfigure, portmap, rpcbind
Posted by Hans-Henry Jakobsen
26 Feb 2008 List rpm package content
To list the contents of a package just run the command
# rpm -ql packagename
Example
# rpm -ql nmap /usr/bin/nmap /usr/share/doc/nmap-3.70 /usr/share/doc/nmap-3.70/COPYING /usr/share/doc/nmap-3.70/COPYING.OpenSSL /usr/share/doc/nmap-3.70/README /usr/share/doc/nmap-3.70/nmap-fingerprinting-article.txt /usr/share/doc/nmap-3.70/nmap.deprecated.txt /usr/share/doc/nmap-3.70/nmap.usage.txt /usr/share/doc/nmap-3.70/nmap_doc.html /usr/share/doc/nmap-3.70/nmap_manpage.html /usr/share/man/man1/nmap.1.gz /usr/share/nmap /usr/share/nmap/nmap-mac-prefixes /usr/share/nmap/nmap-os-fingerprints /usr/share/nmap/nmap-protocols /usr/share/nmap/nmap-rpc /usr/share/nmap/nmap-service-probes /usr/share/nmap/nmap-services
Tags: CentOS, Fedora, RedHat, rpm
Posted by Hans-Henry Jakobsen
25 Feb 2008 My 10 most used linux commands
This is a oneliner bash command to determine my 10 most used linux commands according to my history file
history | awk '{CMD[$2]++;count++;}END { for (a in CMD)print CMD[a] " " CMD[a]/count*100 "% " a;}' | grep -v "./" | column -c3 -s " " -t | sort -nr | nl | head -n10
The result
1 188 37.6% vi
2 38 7.6% ls
3 24 4.8% cat
4 22 4.4% apt-get
5 12 2.4% date
6 11 2.2% tail
7 11 2.2% cd
8 10 2% rm
9 10 2% man
10 9 1.8% basename
It looks like i use vim a lot on my home server. You should try it yourself and see what commands you use the most.
Source: http://linux.byexamples.com
Tags: awk, bash, count, grep, head, nl, sort
Posted by Hans-Henry Jakobsen
25 Feb 2008 Discover online PCs fast
This is as far as I know the fastest way to determine what PCs are online in your network
# nmap -sP 192.168.0.1-255 Starting Nmap 4.53 ( http://insecure.org ) at 2008-02-25 00:01 CET Host 192.168.0.120 appears to be up. Host 192.168.0.140 appears to be up. Host 192.168.0.250 appears to be up. Nmap done: 255 IP addresses (3 host up) scanned in 5.711 seconds
It only took 5.7 seconds to scan all 255 IP addresses and determine if they were online.
Posted by Hans-Henry Jakobsen
