From 89f7dd4248ebdeb1d9219cde7d34ba092be1fac0 Mon Sep 17 00:00:00 2001 From: Junwei Zhao Date: Thu, 18 Apr 2019 16:21:24 +1000 Subject: [PATCH] add CIDR notes --- categories/devops.md | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/categories/devops.md b/categories/devops.md index bd090a4..032b6d2 100644 --- a/categories/devops.md +++ b/categories/devops.md @@ -81,6 +81,49 @@ terraform apply # Apply changes to cluster ![OSI Models](https://raw.githubusercontent.com/wahyd4/knowledge-mind-mapping/master/assets/images/osi-model.png) +## CIDR blocks + +[Wikipedia](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing) + +**Address**|**Difference**|**Mask**|**Addresses**|**Relative**|**Restrictions**|**Typical use**| +:-----:|:-----:|:-----:|:-----:|:-----:|:-----:|:-----:|:-----: +format|to last address| | |to class|on a, b, c and d| | + | | | |A, B, C|(0..255 unless noted)| | +Decimal|2n| | | | | | +a.b.c.d/32|+0.0.0.0|255.255.255.255|1|20|​1⁄256 C| |Host route +a.b.c.d/31|+0.0.0.1|255.255.255.254|2|21|​1⁄128 C|d = 0 ... (2n) ... 254|Point to point links (RFC 3021) +a.b.c.d/30|+0.0.0.3|255.255.255.252|4|22|​1⁄64 C|d = 0 ... (4n) ... 252|Point to point links (glue network) +a.b.c.d/29|+0.0.0.7|255.255.255.248|8|23|​1⁄32 C|d = 0 ... (8n) ... 248|Smallest multi-host network +a.b.c.d/28|+0.0.0.15|255.255.255.240|16|24|​1⁄16 C|d = 0 ... (16n) ... 240|Small LAN +a.b.c.d/27|+0.0.0.31|255.255.255.224|32|25|⅛ C|d = 0 ... (32n) ... 224| +a.b.c.d/26|+0.0.0.63|255.255.255.192|64|26|¼ C|d = 0, 64, 128, 192| +a.b.c.d/25|+0.0.0.127|255.255.255.128|128|27|½ C|d = 0, 128|Large LAN +a.b.c.0/24|+0.0.0.255|255.255.255.0|256|28|1 C| | +a.b.c.0/23|+0.0.1.255|255.255.254.0|512|29|2 C|c = 0 ... (2n) ... 254| +a.b.c.0/22|+0.0.3.255|255.255.252.0|1,024|210|4 C|c = 0 ... (4n) ... 252|Small business +a.b.c.0/21|+0.0.7.255|255.255.248.0|2,048|211|8 C|c = 0 ... (8n) ... 248|Small ISP/ large business +a.b.c.0/20|+0.0.15.255|255.255.240.0|4,096|212|16 C|c = 0 ... (16n) ... 240| +a.b.c.0/19|+0.0.31.255|255.255.224.0|8,192|213|32 C|c = 0 ... (32n) ... 224|ISP/ large business +a.b.c.0/18|+0.0.63.255|255.255.192.0|16,384|214|64 C|c = 0, 64, 128, 192| +a.b.c.0/17|+0.0.127.255|255.255.128.0|32,768|215|128 C|c = 0, 128| +a.b.0.0/16|+0.0.255.255|255.255.0.0|65,536|216|256 C = B| | +a.b.0.0/15|+0.1.255.255|255.254.0.0|131,072|217|2 B|b = 0 ... (2n) ... 254| +a.b.0.0/14|+0.3.255.255|255.252.0.0|262,144|218|4 B|b = 0 ... (4n) ... 252| +a.b.0.0/13|+0.7.255.255|255.248.0.0|524,288|219|8 B|b = 0 ... (8n) ... 248| +a.b.0.0/12|+0.15.255.255|255.240.0.0|1,048,576|220|16 B|b = 0 ... (16n) ... 240| +a.b.0.0/11|+0.31.255.255|255.224.0.0|2,097,152|221|32 B|b = 0 ... (32n) ... 224| +a.b.0.0/10|+0.63.255.255|255.192.0.0|4,194,304|222|64 B|b = 0, 64, 128, 192| +a.b.0.0/9|+0.127.255.255|255.128.0.0|8,388,608|223|128 B|b = 0, 128| +a.0.0.0/8|+0.255.255.255|255.0.0.0|16,777,216|224|256 B = A| |Largest IANA block allocation +a.0.0.0/7|+1.255.255.255|254.0.0.0|33,554,432|225|2:00 am|a = 0 ... (2n) ... 254| +a.0.0.0/6|+3.255.255.255|252.0.0.0|67,108,864|226|4:00 am|a = 0 ... (4n) ... 252| +a.0.0.0/5|+7.255.255.255|248.0.0.0|134,217,728|227|8:00 am|a = 0 ... (8n) ... 248| +a.0.0.0/4|+15.255.255.255|240.0.0.0|268,435,456|228|16 A|a = 0 ... (16n) ... 240| +a.0.0.0/3|+31.255.255.255|224.0.0.0|536,870,912|229|32 A|a = 0 ... (32n) ... 224| +a.0.0.0/2|+63.255.255.255|192.0.0.0|1,073,741,824|230|64 A|a = 0, 64, 128, 192| +a.0.0.0/1|+127.255.255.255|128.0.0.0|2,147,483,648|231|128 A|a = 0, 128| +0.0.0.0/0|+255.255.255.255|0.0.0.0|4,294,967,296|232|256 A| | + # tools ## git - cherrypick