Networking

Network notes

Private address ranges

RFC 1918 name	IP address range	Number of addresses	Largest CIDR block	Host ID size	Mask bits	description
24 bit block	10.0.0.0-10.255.255.255	16,777,216	10.0.0.8/8 255.0.0.0	24 bits	8 bits	single class A network
20 bit block	176.16.0.0-172.31.255.255	1,048,576	176.16.0.0/12 255.240.0.0	20 bits	12 bits	16 contiguous class B networks
16 bit block	192.168.0.0-192.168.255.255	65,536	192.168.0.0/16 255.255.0.0	16 bits	16 bits	256 contiguous class C networks

network testing

speedtest

• without the cruft

TLS

• Test certificate chain openssl\ s_client\ -showcerts\ -connect google.com:443