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Google Search Guide

Tuesday, 30 December 2008 22:54 General Info - General Info

Google Advance Search Operators

"google example"	phrase	Pages containing the exact phrase "google example"
example -word	exclude	Pages containing the word example but not the word "word"
example site:www.example.com	site	Pages containing example within website www.example.com
~example	similar	Pages containing words similar to example
example filetype:ppt	filetype	Documents containing the word example and are ppt extenstions
example\|google	either	Pages containing either the word example or google
example 1..2000	number range	Pages containing the word example and numbers 1 to 2000
define:example	define	Define the word example
example inurl:fir3	url	Pages containing fir3 in URL and the word example
intitle:example	title	Pages with all words in title
intitle:example	title	Pages with the word example in title
related:www.fir3net.com	related	Websites similar to www.fir3net.com

Custom Searches (using the above)

-inurl:htm -inurl:html intitle:"index of" mp3 "Artist Name"	Music
-inurl:htm -inurl:html -inurl:php intitle:"index of" (mpg\|mov\|avi\|wmv) "Movie Name"	Movies

Notes - MTU and PMTU

Thursday, 18 December 2008 22:23 General Info - General Info

This is by no-means a full guide to MTU or PMTU but a small collection of notes,

Protocol Overhead

VLAN Tag (Dot1q)	4 Bytes
MPLS	4 Bytes
IP	20 Bytes
TCP Header	20 Bytes
UDP Header	8 Bytes
ICMP Header	8 Bytes

Example,

To send a ping with a full 1500 byte packet , you can run the command below. The 1550 bytes will consist of,

ICMP Payload (1472 bytes) + ICMP Header (20 bytes) + IP Header (20 bytes)

ping -s 1500 [destination ip]

MSS - Maximum Segment Size

Thursday, 18 December 2008 17:32 General Info - General Info

This Maximum Segment Size (MSS) announcement (often mistakenly called a negotiation) is sent from the data receiver to the data sender and says "I can accept TCP segments up to size X". The size (X) may be larger or smaller than the default.
The MSS can be used completely independently in each direction of data flow. The result may be quite different maximum
sizes in the two directions.

Below you can see an example where 192.168.1.100 is saying he can accept a MSS of 1280 for all future TCP segments. And 10.1.1.100 can only accept MSS`s of 1460 for all future TCP segments.

10.1.1.100   192.1.1.100   TCP   39884 > 22 [SYN] Seq=0 Len=0 MSS=1460 TSV=556758839 TSER=0 WS=7
192.1.1.100   10.1.1.100   TCP   22 > 39884 [SYN, ACK] Seq=0 Ack=1 Win=16484 Len=0 MSS=1280 WS=0 TSV=522800 9
10.1.1.100   192.1.1.100   TCP   39884 > 22 [ACK] Seq=1 Ack=1 Win=5888 Len=0 TSV=556758839 TSER=522800