# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
allow-hotplug eth0
auto eth0
iface eth0 inet dhcp
auto eth0:1
iface eth0:1 inet static
address 192.168.31.81
netmask 255.255.255.0
network 192.168.31.0
gateway 192.168.31.254
awk '/^--|^$/ {print; next} !/;$/ {printf("%s ", $0); next} { print }'#!/usr/bin/env python
# Define nameless (lambda) function.
# This means that we:
# a) Create a function object.
# b) Assign "f" a reference to this object (function).
f = lambda x: x+42
# Call this function, passing it 1 variable.
print f(0)
# Do the same thing, simply replace the nameless with a "FULL" function.
def func(x):
return x + 42
# Assign variables "g" a reference to function "func"
g = func
# Call this function, passing it 1 variable.
print g(0)
@ 500 IN MX 1 mx1.rfsee.net.Which basicly says that my main (and only) MX server for the domain rfsee.net is "mx1.rfsee.net", the second line is a simple A record resolving the name to my server IP address.
mx1.rfsee.net. 500 IN A 205.134.246.209
$ cat /etc/aliasesremember to run newaliases after each edit made to this file, otherwise postfix won't catch up with changes. Reason for this being: postfix uses hash based lookup for the aliases file, when you run newaliases it actually created aliases.db and thats the file postfix reads.
# /etc/aliases
mailer-daemon: postmaster
nobody: root
hostmaster: root
usenet: root
news: root
webmaster: root
www: root
ftp: root
abuse: root
noc: root
security: root
root: hq4ever
postmaster: hq4ever
foo: hq4ever@gmail.com
rfsee.net. 28800 IN TXT "v=spf1 mx include:gmail.com -all"which says, for domain "rfsee.net", use spf version 1, trust every mx defined in the dns, and also trust every mx defined in the dns for the domain gmail.com, everything else is bad so block it. The include:gmail.com part is very nice, because I mostly do my emailing from gmail, being able to change my FROM address could fail if I hadn't added this "include" record.
aptitude install module-init-toolsLets bluntly ignore that Stanford warnings about "bind on localhost" and configure our bind9 to listen ONLY on localhost. The logic is - We are setting up a local caching DNS server, I don't want others to waste my bandwidth using me as their DNS resolver (I wouldn't mind doing it for you temporarily if you ask me to, but not globally for the whole worm infesteded Internet). So we follow the instructions here[2], [3]
aptitude install bind9
aptitude install dnsutils
options {
directory "/var/cache/bind";
// If there is a firewall between you and nameservers you want
// to talk to, you might need to uncomment the query-source
// directive below. Previous versions of BIND always asked
// questions using port 53, but BIND 8.1 and later use an unprivileged
// port by default.
// query-source address * port 53;
// If your ISP provided one or more IP addresses for stable
// nameservers, you probably want to use them as forwarders.
// Uncomment the following block, and insert the addresses replacing
// the all-0's placeholder.
// forwarders {
// 0.0.0.0;
// };
auth-nxdomain no; # conform to RFC1035
listen-on-v6 { 0:0:0:0:0:0:0:1; };
listen-on { 127.0.0.1; };
};
root@srv-il:/# dig @127.0.0.1 example.com
; <<>> DiG 9.3.2-P1 <<>> @127.0.0.1 example.com
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14378 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 ;; QUESTION SECTION: ;example.com. IN A ;; ANSWER SECTION: example.com. 172800 IN A 192.0.34.166
;; AUTHORITY SECTION:
example.com. 21600 IN NS a.iana-servers.net.
example.com. 21600 IN NS b.iana-servers.net.
;; ADDITIONAL SECTION:
a.iana-servers.net. 172799 IN A 192.0.34.43
b.iana-servers.net. 172799 IN A 193.0.0.236
;; Query time: 1390 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Sat Jan 13 17:08:50 2007
;; MSG SIZE rcvd: 125
root@srv-il:/# dig @127.0.0.1 example.com
; <<>> DiG 9.3.2-P1 <<>> @127.0.0.1 example.com
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40396 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 ;; QUESTION SECTION: ;example.com. IN A ;; ANSWER SECTION: example.com. 172795 IN A 192.0.34.166
;; AUTHORITY SECTION:
example.com. 21595 IN NS b.iana-servers.net.
example.com. 21595 IN NS a.iana-servers.net.
;; ADDITIONAL SECTION:
a.iana-servers.net. 172794 IN A 192.0.34.43
b.iana-servers.net. 172794 IN A 193.0.0.236
;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Sat Jan 13 17:08:55 2007
;; MSG SIZE rcvd: 125
nameserver 127.0.0.1* Note: if "nameserver 127.0.0.1" has "magicly" appeared in your resolve.conf after you installed bind the means you use resolvconf(8), bind9 has a hook in it's init script for resolveconf so this step can be safely skipped.
search gplhost.com
nameserver 66.251.193.21
nameserver 205.134.246.194
To copy an entire block device or a single partition from one machine to the other over the network, use the following procedure :
dd if=/dev/hda bs=1k conv=sync,noerror | gzip -c | ssh -c blowfish user@hostname "gzip -d | dd of=/dev/hda bs=1k"
You can also use the great g4u (2) project that is based on BSD and is amazing in it's simplicity and usefulness.
Good for 1-to-1 copy of server machines, great for rapid restore in case of a crash.
Also can be used for intrusion detection analyses: Just copy the hard drive and use all the the data analyzing software you want on the clone, knowing that the original hard drive is still intact.
