subnet_cheatsheet.md (10578B)
1 # subnet cheatsheet 2 3 https://oav.net/mirrors/cidr.html 4 5 ``` 6 Netmask Netmask (binary) CIDR Notes 7 _____________________________________________________________________________ 8 255.255.255.255 11111111.11111111.11111111.11111111 /32 Host (single addr) 9 255.255.255.254 11111111.11111111.11111111.11111110 /31 Unuseable 10 255.255.255.252 11111111.11111111.11111111.11111100 /30 2 useable 11 255.255.255.248 11111111.11111111.11111111.11111000 /29 6 useable 12 255.255.255.240 11111111.11111111.11111111.11110000 /28 14 useable 13 255.255.255.224 11111111.11111111.11111111.11100000 /27 30 useable 14 255.255.255.192 11111111.11111111.11111111.11000000 /26 62 useable 15 255.255.255.128 11111111.11111111.11111111.10000000 /25 126 useable 16 255.255.255.0 11111111.11111111.11111111.00000000 /24 "Class C" 254 useable 17 18 255.255.254.0 11111111.11111111.11111110.00000000 /23 2 Class C's 19 255.255.252.0 11111111.11111111.11111100.00000000 /22 4 Class C's 20 255.255.248.0 11111111.11111111.11111000.00000000 /21 8 Class C's 21 255.255.240.0 11111111.11111111.11110000.00000000 /20 16 Class C's 22 255.255.224.0 11111111.11111111.11100000.00000000 /19 32 Class C's 23 255.255.192.0 11111111.11111111.11000000.00000000 /18 64 Class C's 24 255.255.128.0 11111111.11111111.10000000.00000000 /17 128 Class C's 25 255.255.0.0 11111111.11111111.00000000.00000000 /16 "Class B" 26 27 255.254.0.0 11111111.11111110.00000000.00000000 /15 2 Class B's 28 255.252.0.0 11111111.11111100.00000000.00000000 /14 4 Class B's 29 255.248.0.0 11111111.11111000.00000000.00000000 /13 8 Class B's 30 255.240.0.0 11111111.11110000.00000000.00000000 /12 16 Class B's 31 255.224.0.0 11111111.11100000.00000000.00000000 /11 32 Class B's 32 255.192.0.0 11111111.11000000.00000000.00000000 /10 64 Class B's 33 255.128.0.0 11111111.10000000.00000000.00000000 /9 128 Class B's 34 255.0.0.0 11111111.00000000.00000000.00000000 /8 "Class A" 35 36 254.0.0.0 11111110.00000000.00000000.00000000 /7 37 252.0.0.0 11111100.00000000.00000000.00000000 /6 38 248.0.0.0 11111000.00000000.00000000.00000000 /5 39 240.0.0.0 11110000.00000000.00000000.00000000 /4 40 224.0.0.0 11100000.00000000.00000000.00000000 /3 41 192.0.0.0 11000000.00000000.00000000.00000000 /2 42 128.0.0.0 10000000.00000000.00000000.00000000 /1 43 0.0.0.0 00000000.00000000.00000000.00000000 /0 IP space 44 ``` 45 46 ``` 47 Net Host Total 48 Net Addr Addr Addr Number 49 Class Range NetMask Bits Bits of hosts 50 ---------------------------------------------------------- 51 A 0-127 255.0.0.0 8 24 16777216 (i.e. 114.0.0.0) 52 B 128-191 255.255.0.0 16 16 65536 (i.e. 150.0.0.0) 53 C 192-254 255.255.255.0 24 8 256 (i.e. 199.0.0.0) 54 D 224-239 (multicast) 55 E 240-255 (reserved) 56 F 208-215 255.255.255.240 28 4 16 57 G 216/8 ARIN - North America 58 G 217/8 RIPE NCC - Europe 59 G 218-219/8 APNIC 60 H 220-221 255.255.255.248 29 3 8 (reserved) 61 K 222-223 255.255.255.254 31 1 2 (reserved) 62 (ref: RFC1375 & http://www.iana.org/assignments/ipv4-address-space ) 63 ( http://www.iana.org/numbers.htm ) 64 ---------------------------------------------------------- 65 ``` 66 67 The current list of special use prefixes: 68 ``` 69 0.0.0.0/8 70 127.0.0.0/8 71 192.0.2.0/24 72 10.0.0.0/8 73 172.16.0.0/12 74 192.168.0.0/16 75 169.254.0.0/16 76 all D/E space 77 ``` 78 - (ref: RFC1918 http://www.rfc-editor.org/rfc/rfc1918.txt ) 79 - ( or ftp://ftp.isi.edu/in-notes/rfc1918.txt ) 80 - (rfc search: http://www.rfc-editor.org/rfcsearch.html ) 81 - ( http://www.ietf.org/ietf/1id-abstracts.txt ) 82 - ( http://www.ietf.org/shadow.html ) 83 84 85 Martians: (updates at: www.iana.org/assignments/ipv4-address-space ) 86 ``` 87 no ip source-route 88 access-list 100 deny ip host 0.0.0.0 any 89 deny ip 0.0.0.0 0.255.255.255 any log ! antispoof 90 deny ip 0.0.0.0 0.255.255.255 0.0.0.0 255.255.255.255 ! antispoof 91 deny ip any 255.255.255.128 0.0.0.127 ! antispoof 92 deny ip host 0.0.0.0 any log ! antispoof 93 deny ip host [router intf] [router intf] ! antispoof 94 deny ip xxx.xxx.xxx.0 0.0.0.255 any log ! lan area 95 deny ip 0/8 0.255.255.255 any log ! IANA - Reserved 96 deny ip 1/8 0.255.255.255 any log ! IANA - Reserved 97 deny ip 2/8 0.255.255.255 any log ! IANA - Reserved 98 deny ip 5/8 0.255.255.255 any log ! IANA - Reserved 99 deny ip 7/8 0.255.255.255 any log ! IANA - Reserved 100 deny ip 10.0.0.0 0.255.255.255 any log ! IANA - Private Use 101 deny ip 23/8 0.255.255.255 any log ! IANA - Reserved 102 deny ip 27/8 0.255.255.255 any log ! IANA - Reserved 103 deny ip 31/8 0.255.255.255 any log ! IANA - Reserved 104 deny ip 36-37/8 0.255.255.255 any log ! IANA - Reserved 105 deny ip 39/8 0.255.255.255 any log ! IANA - Reserved 106 deny ip 41-42/8 0.255.255.255 any log ! IANA - Reserved 107 deny ip 50/8 0.255.255.255 any log ! IANA - Reserved 108 deny ip 58-60/8 0.255.255.255 any log ! IANA - Reserved 109 deny ip 69-79/8 0.255.255.255 any log ! IANA - Reserved 110 deny ip 82-95/8 0.255.255.255 any log ! IANA - Reserved 111 deny ip 96-126/8 0.255.255.255 any log ! IANA - Reserved 112 deny ip 127/8 0.255.255.255 any log ! IANA - Reserved 113 deny ip 169.254.0.0 0.0.255.255 any log ! link-local network 114 deny ip 172.16.0.0 0.15.255.255 any log ! reserved 115 deny ip 192.168.0.0 0.0.255.255 any log ! reserved 116 deny ip 192.0.2.0 0.0.0.255 any log ! test network 117 deny ip 197/8 0.255.255.255 any log ! IANA - Reserved 118 deny ip 220/8 0.255.255.255 any log ! IANA - Reserved 119 deny ip 222-223/8 0.255.255.255 any log ! IANA - Reserved 120 deny ip 224.0.0.0 31.255.255.255 any log ! multicast 121 deny ip 224.0.0.0 15.255.255.255 any log ! unless MBGP-learned routes 122 deny ip 224-239/8 0.255.255.255 any log ! IANA - Multicast 123 deny ip 240-255/8 0.255.255.255 any log ! IANA - Reserved 124 ``` 125 126 ``` 127 filtered source addresses 128 0/8 ! broadcast 129 10/8 ! RFC 1918 private 130 127/8 ! loopback 131 169.254.0/16 ! link local 132 172.16.0.0/12 ! RFC 1918 private 133 192.0.2.0/24 ! TEST-NET 134 192.168.0/16 ! RFC 1918 private 135 224.0.0.0/4 ! class D multicast 136 240.0.0.0/5 ! class E reserved 137 248.0.0.0/5 ! reserved 138 255.255.255.255/32 ! broadcast 139 ``` 140 141 ARIN administrated blocks: (http://www.arin.net/regserv/IPStats.html) 142 ``` 143 24.0.0.0/8 (portions of) 144 63.0.0.0/8 145 64.0.0.0/8 146 65.0.0.0/8 147 66.0.0.0/8 148 196.0.0.0/8 149 198.0.0.0/8 150 199.0.0.0/8 151 200.0.0.0/8 152 204.0.0.0/8 153 205.0.0.0/8 154 206.0.0.0/8 155 207.0.0.0/8 156 208.0.0.0/8 157 209.0.0.0/8 158 216.0.0.0/8 159 ``` 160 ---------------------------------------------------------- 161 162 well known ports: (rfc1700.txt) 163 - www.iana.org/assignments/port-numbers 164 165 protocol numbers: 166 - www.iana.org/assignments/protocol-numbers 167 - www.iana.org/numbers.htm 168 169 ICMP(Types/Codes) 170 ``` 171 Testing Destination Reachability & Status 172 (0/0) Echo-Reply 173 (8/0) Echo 174 Unreachable Destinations 175 (3/0) Network Unreachable 176 (3/1) Host Unreachable 177 (3/2) Protocol Unreachable 178 (3/3) Port Unreachable 179 (3/4) Fragmentaion Needed and DF set (Pkt too big) 180 (3/5) Source Route Failed 181 (3/6) Network Unknown 182 (3/7) Host Unknown 183 (3/9) DOD Net Prohibited 184 (3/10) DOD Host Prohibited 185 (3/11) Net TOS Unreachable 186 (3/12) Host TOS Unreachable 187 (3/13) Administratively Prohibited 188 (3/14) Host Precedence Unreachable 189 (3/15) Precedence Unreachable 190 Flow Control 191 (4/0) Source-Quench [RFC 1016] 192 Route Change Requests from Gateways 193 (5/0) Redirect Datagrams for the Net 194 (5/1) Redirect Datagrams for the Host 195 (5/2) Redirect Datagrams for the TOS and Net 196 (5/3) Redirect Datagrams for the TOS and Host 197 Router 198 (6/-) Alternate-Address 199 (9/0) Router-Advertisement 200 (10/0) Router-Solicitation 201 Detecting Circular or Excessively Long Routes 202 (11/0) Time to Live Count Exceeded 203 (11/1) Fragment Reassembly Time Exceeded 204 Reporting Incorrect Datagram Headers 205 (12/0) Parameter-Problem 206 (12/1) Option Missing 207 (12/2) No Room for Option 208 Clock Synchronization and Transit Time Estimation 209 (13/0) Timestamp-Request 210 (14/0) Timestamp-Reply 211 Obtaining a Network Address (RARP Alternative) 212 (15/0) Information-Request 213 (16/0) Information-Reply 214 Obtaining a Subnet Mask [RFC 950] 215 (17/0) Address Mask-Request 216 (18/0) Address Mask-Reply 217 Other 218 (30/0) Traceroute 219 (31/0) Conversion-Error 220 (32/0) Mobile-Redirect 221 ``` 222 223 Ref: [RFC 792] [RFC 896] [RFC 950] [RFC 1016] 224 www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_5_3/cofigide/qos.htm#19774 225 226 227 228 ``` 229 Decimal system Prefix's 230 Factor Exponent Prefix 231 --------------------------------------------------- 232 1 000 000 000 000 000 000 000 000...10^24....yotta 233 1 000 000 000 000 000 000 000...10^21....zetta 234 1 000 000 000 000 000 000...10^18....exa 235 1 000 000 000 000 000...10^15....peta 236 1 000 000 000 000...10^12....tera 237 1 000 000 000...10^9.....giga 238 1 000 000...10^6.....mega 239 1 000...10^3.....kilo 240 100...10^2.....hecto 241 10...10^1.....deka 242 0.1...10^-1....deci 243 0.01...10^-2....centi 244 0.001...10^-3....milli 245 0.000 001...10^-6....micro 246 0.000 000 001...10^-9....nano 247 0.000 000 000 001...10^-12...pico 248 0.000 000 000 000 001...10^-15...femto 249 0.000 000 000 000 000 001...10^-18...atto 250 0.000 000 000 000 000 000 001...10^-21...zepto 251 0.000 000 000 000 000 000 000 001...10^-24...yocto 252 --------------------------------------------------- 253 254 ``` 255 - Convert Fahrenheit <> Celsius: 256 - Celsius = (Fahrenheit - 32) / 1.8 257 - Fahrenheit = (Celsius * 1.8) + 32 258 259 260 last updated: 4jul02 261 262 263