Αρχείο κατηγορίας favorite tools

ipv6calc: ipv6 address conversion utility

ipv6calc is a swiss-army knife utility to manipulate ipv6 addresses. It can be used to convert IPv6 addresses from one format to another and extract embedded information.

$ ipv6calc -q --out revnibbles.arpa 2002:d4fb:e54::1
1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.4.5.e.0.b.f.4.d.2.0.0.2.ip6.arpa.
(the above can also be obtained easily using dig -x 2002:d4fb:e54::1)
$ ipv6calc -q --action conv6to4 --in ipv4 193.92.110.1 --out ipv6
2002:c15c:6e01::

$ ipv6calc -q --action conv6to4 --in ipv6 2002:c15c:6e01:: --out ipv4
193.92.110.1

$ ipv6calc -q --addr_to_uncompressed 2002:c15c:6e01::
2002:c15c:6e01:0:0:0:0:0

$ ipv6calc -q -i 2002:c15c:6e01::
Address type: unicast, 6to4, global-unicast, productive
Address type is 6to4 and included IPv4 address is: 193.92.110.1
IPv4 registry for 6to4 address: RIPENCC
Address type has SLA: 0000
Interface identifier: 0000:0000:0000:0000
Interface identifier is probably manual set or based on a local EUI-64 identifier
$ ipv6calc -q --action geneui64 00:1f:c6:7e:83:b8
021f:c6ff:fe7e:83b8

$ ipv6calc -q -i fe80::21f:c6ff:fe7e:83b8/64
Address type: unicast, link-local
Registry for address: reserved
Interface identifier: 021f:c6ff:fe7e:83b8
EUI-48/MAC address: 00:1f:c6:7e:83:b8
MAC is a global unique one
MAC is an unicast one
OUI is: ASUSTek COMPUTER INC.

Free Linux Journal Issue 02/2010

Είμαι συνδρομητής του Linux Journal για περίπου 10 χρόνια.. Τα τελευταία δύο, εκτός από την παραδοσιακή έντυπη έκδοση πήρα και το Digital Subscription σε PDF. Μαζί με το Linux Journal Archive CD η συλλογή μου πλέον είναι πλήρης..

Τώρα μου έμειναν ένα σωρό hard-copies του LJ που πιάνουν χώρο.. ή θα τα δώσω σε κάποιο τοπικό εργαστήριο Linux Users Group (thelug?) ή θα τα ανακυκλώσω..

Αυτό το μήνα πάντως, προσφέρουν εντελώς δωρεάν το τεύχος του Φεβρουαρίου 2010 σε PDF..

Κατεβάστε το feb2010-special.pdf και καλη ανάγνωση!

UPDATE: Πάρτε και μια γεύση του επόμενου τεύχους LJ (System Administration): http://ow.ly/16sdFz

UPDATE2: Ο @boukouvalas επικοινώνησε μαζί μου για τα hard-copies στο εργαστήριο του thelug :)

RANCID – the Really Awesome New Cisco confIg Differ

Do you want to backup all your router configurations in one location? Keep them under revision control? Also include their hardware specs, modules etc? grep for serial numbers or configuration directives in all of them? Execute a series of command in some of them? Generate graphs of your network topology automagically? Run security audits on your configs? See what changed last night by other co-workers?

Meet RANCID, the Really Awesome New Cisco confIg Differ, by Shrubbery Networks!

RANCID monitors a router’s (or more generally a device’s) configuration, including software and hardware (cards, serial numbers, etc) and uses CVS or Subversion to maintain history of changes.

RANCID does this by the very simple process summarized here:

  • login to each device in the router table (router.db),
  • run various commands to get the information that will be saved,
  • cook the output; re-format, remove oscillating or incrementing data,
  • email any differences from the previous collection to a mail list,
  • and finally commit those changes to the revision control system

Rancid currently supports Cisco routers, Catalyst switches, Juniper routers, F5 devices, HP Procurve switches and a host of others.

Using a tool like ViewVC, WebSVN or chora to put your repository on the web is a must.


A possible alternative is ZipTie, nowadays known as NetworkAuthority Inventory by AlterPoint.

Munin – performance monitoring tool

My favorite performance monitoring tool: Munin by linpro.

Munin monitoring tool surveys all your computers and remembers what it saw. It presents all the information in graphs through a web interface. Its emphasis is on plug and play capabilities. After completing a installation a high number of monitoring plugins will be playing with no more effort.

Using Munin you can easily monitor the performance of your computers, networks, SANs, applications, weather measurements and whatever comes to mind. It makes it easy to determine «what’s different today» when a performance problem crops up. It makes it easy to see how you’re doing capacity-wise on any resources.

Munin uses the excellent RRDTool and the framework is written in Perl, while plugins may be written in any language. Munin has a master/node architecture in which the master connects to all the nodes at regular intervals and asks them for data. It then stores the data in RRD files, and (if needed) updates the graphs. One of the main goals has been ease of creating new plugins (graphs).

Previous articles in my blog about munin:

mtr: Matt’s traceroute

Another favorite tool.. mtr by Matt Kimball.

mtr combines the functionality of the ‘traceroute’ and ‘ping’ programs in a single network diagnostic tool.As mtr starts, it investigates the network connection between the host mtr runs on and a user-specified destination host. After it determines the address of each network hop between the machines, it sends a sequence ICMP ECHO requests to each one to determine the quality of the link to each machine. As it does this, it prints running statistics about each machine.