zero-sys.net
Software Engineering, Administration, IT-Services & Consulting
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mailrelay
... from your mail-server 
telnet relay-test.mail-abuse.org
Erstellt: 12.05.2006 11:19
Letzte Änderung: 12.05.2006 11:19


snmpd / smux
bind smux to loopback-interface 
snmpd.conf:
...
smuxsocket 127.0.0.1
...
Erstellt: 17.05.2006 14:25
Letzte Änderung: 26.05.2006 12:22


netmask calculators
Erstellt: 18.05.2006 12:09
Letzte Änderung: 18.05.2006 12:09


iptables limit
Limit the number of connections to ssh-port: 
/sbin/iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
/sbin/iptables -A INPUT -p tcp --dport 22 -m limit --limit 2/minute --limit-burst 1 -m state --state NEW -j ACCEPT
/sbin/iptables -A INPUT -p tcp --dport 22 -j DROP
a better limit may be the hashlimit: 
/sbin/iptables  -A INPUT -m tcp -p tcp --dport 22 -m hashlimit  \ 
 --hashlimit 1/min --hashlimit-mode srcip \ 
 --hashlimit-name ssh -m state --state NEW -j ACCEPT
or
/sbin/iptables -A INPUT -p tcp -i eth0 --syn --dport 22 \ 
 -m hashlimit --hashlimit-name SSH --hashlimit 4/minute --hashlimit-burst 1 \ 
 --hashlimit-mode srcip --hashlimit-htable-expire 600000 -j ACCEPT
Erstellt: 26.05.2006 13:18
Letzte Änderung: 16.06.2006 12:40


DiskImages
If you may need to work on diskimages: ....

use losetup to setup a loopdevice: 
losetup /dev/loop0 /tmp/img

use a partitioning tool to setup the partitions ...

use fdisk to calculate offset: 
fdisk -lu IMAGE
where IMAGE may be the image-file or the loop-device

use offset for losetup to setup only one partition as loop: 
losetup -o OFFSET /dev/loop0 /tmp/img
or for mounting: 
mount -o loop=/dev/loop0;,offset=OFFSET /tmp/img /mnt /tmp/img
Erstellt: 01.06.2006 16:00
Letzte Änderung: 16.06.2006 12:40


ICMP / traceroute results
I - Interrupted
T - Timeout
N - ICMP Net Unreachable
H - ICMP Host Unreachable
P - ICMP Unknown Protocol
U - ICMP Unreachable Port
A - ICMP Administratively Prohibited
Erstellt: 29.01.2007 10:56
Letzte Änderung: 29.01.2007 10:56