technology/networking/subnet_cheatsheet.md
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@@ -2,6 +2,7 @@
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https://oav.net/mirrors/cidr.html
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+```
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Netmask Netmask (binary) CIDR Notes
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_____________________________________________________________________________
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255.255.255.255 11111111.11111111.11111111.11111111 /32 Host (single addr)
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@@ -40,7 +41,9 @@ _____________________________________________________________________________
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192.0.0.0 11000000.00000000.00000000.00000000 /2
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128.0.0.0 10000000.00000000.00000000.00000000 /1
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0.0.0.0 00000000.00000000.00000000.00000000 /0 IP space
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+```
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46
+```
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Net Host Total
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Net Addr Addr Addr Number
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Class Range NetMask Bits Bits of hosts
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@@ -59,8 +62,10 @@ K 222-223 255.255.255.254 31 1 2 (reserved)
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(ref: RFC1375 & http://www.iana.org/assignments/ipv4-address-space )
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( http://www.iana.org/numbers.htm )
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----------------------------------------------------------
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+```
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The current list of special use prefixes:
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+```
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0.0.0.0/8
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127.0.0.0/8
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192.0.2.0/24
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@@ -69,14 +74,16 @@ The current list of special use prefixes:
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192.168.0.0/16
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169.254.0.0/16
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all D/E space
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-(ref: RFC1918 http://www.rfc-editor.org/rfc/rfc1918.txt )
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-( or ftp://ftp.isi.edu/in-notes/rfc1918.txt )
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-(rfc search: http://www.rfc-editor.org/rfcsearch.html )
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-( http://www.ietf.org/ietf/1id-abstracts.txt )
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-( http://www.ietf.org/shadow.html )
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+```
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+- (ref: RFC1918 http://www.rfc-editor.org/rfc/rfc1918.txt )
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+- ( or ftp://ftp.isi.edu/in-notes/rfc1918.txt )
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+- (rfc search: http://www.rfc-editor.org/rfcsearch.html )
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+- ( http://www.ietf.org/ietf/1id-abstracts.txt )
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+- ( http://www.ietf.org/shadow.html )
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Martians: (updates at: www.iana.org/assignments/ipv4-address-space )
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+```
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no ip source-route
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access-list 100 deny ip host 0.0.0.0 any
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deny ip 0.0.0.0 0.255.255.255 any log ! antispoof
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@@ -114,7 +121,9 @@ Martians: (updates at: www.iana.org/assignments/ipv4-address-space )
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deny ip 224.0.0.0 15.255.255.255 any log ! unless MBGP-learned routes
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deny ip 224-239/8 0.255.255.255 any log ! IANA - Multicast
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deny ip 240-255/8 0.255.255.255 any log ! IANA - Reserved
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+```
117 125
126
+```
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filtered source addresses
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0/8 ! broadcast
120 129
10/8 ! RFC 1918 private
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@@ -127,8 +136,10 @@ filtered source addresses
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240.0.0.0/5 ! class E reserved
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248.0.0.0/5 ! reserved
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255.255.255.255/32 ! broadcast
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+```
130 140
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ARIN administrated blocks: (http://www.arin.net/regserv/IPStats.html)
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+```
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24.0.0.0/8 (portions of)
133 144
63.0.0.0/8
134 145
64.0.0.0/8
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@@ -145,16 +156,18 @@ ARIN administrated blocks: (http://www.arin.net/regserv/IPStats.html)
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208.0.0.0/8
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209.0.0.0/8
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216.0.0.0/8
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+```
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----------------------------------------------------------
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well known ports: (rfc1700.txt)
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- www.iana.org/assignments/port-numbers
163
+ - www.iana.org/assignments/port-numbers
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153 165
protocol numbers:
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- www.iana.org/assignments/protocol-numbers
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- www.iana.org/numbers.htm
166
+ - www.iana.org/assignments/protocol-numbers
167
+ - www.iana.org/numbers.htm
156 168
157 169
ICMP(Types/Codes)
170
+```
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Testing Destination Reachability & Status
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(0/0) Echo-Reply
160 173
(8/0) Echo
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@@ -205,12 +218,14 @@ ICMP(Types/Codes)
205 218
(30/0) Traceroute
206 219
(31/0) Conversion-Error
207 220
(32/0) Mobile-Redirect
221
+```
208 222
209 223
Ref: [RFC 792] [RFC 896] [RFC 950] [RFC 1016]
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www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_5_3/cofigide/qos.htm#19774
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+```
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Decimal system Prefix's
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Factor Exponent Prefix
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---------------------------------------------------
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@@ -236,9 +251,10 @@ Decimal system Prefix's
236 251
0.000 000 000 000 000 000 000 001...10^-24...yocto
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---------------------------------------------------
238 253
239
-Convert Fahrenheit <> Celsius:
240
- Celsius = (Fahrenheit - 32) / 1.8
241
- Fahrenheit = (Celsius * 1.8) + 32
254
+```
255
+- Convert Fahrenheit <> Celsius:
256
+ - Celsius = (Fahrenheit - 32) / 1.8
257
+ - Fahrenheit = (Celsius * 1.8) + 32
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last updated: 4jul02