摘要：libev First let's talk about libev, it is a lib used in ss. The coding style of libev is ugly. To see man page of libev by: man ./ev.3 3 files need to 阅读全文

摘要：SACK: (selective ack), it is an option added to normal ack packets. Normally sack can specify at most 4 groups of seq_start, seq_end. Meaning bytes at 阅读全文

摘要：How the algorithm and formula are implemented seem trivial, the most important of the passage's idea is the definition of 'conservation of packets'. F 阅读全文

摘要：At kernel init, each logical core has a thread called ksoftirq/%d running. These threads are brought up by the initial function net_dev_init(). While 阅读全文

摘要：According to RedHat accessories, TCP_NODELAY: each call to write(fd, buf...) will be sent out as packet. This leads to poor overall performance when m 阅读全文

摘要：Before using stap, the kernel-debuginfo-$(uname -r), kernel-debuginfo-common-$(uname -m)-$(uname -r) and kernel-devel-$(uname -r) should be installed. 阅读全文

摘要：from here. php basics in PHP, variables are defined as $_alphanum variables should always prefixed a $ variables defined/assigned outside of a functio 阅读全文

摘要：To use composer, first system must satisfy php environment: To install composer, try either: enable packagist repo globally: [its speed seems not fast 阅读全文

摘要：SNMP is a protocol that enables server remote-info-exchange. Which according to wikipedia: it [collecting and organizing information about managed dev 阅读全文

摘要：most common cases: Very important knowledge: -sS: default if using root/admin with nmap (Syn scan) -sT: default if using normal user with nmap (TCP co 阅读全文

摘要：Find the authoritative server of a domain, by: find actual IP of a sub-domain, by: What is authoritative server of dns? [Quote]An authoritative name s 阅读全文

摘要：if using dpdk, then OvS' datapath folder is ignored. Only OvS' userspace code are in use. According to manpages of ovs-vsctl/ovs-dpctl, it says that t 阅读全文

摘要：In short, we have some sort of algorithms to gen pair of private and public keys. The public key is stored in a certificate and the private key is usu 阅读全文

摘要：The following is concluded from here. Consider we have 2 interfaces: eth0 & eth1 bond the two interface: in ifcfg-eth0/ifcfg-eth1: remove IP/MASK/GW/U 阅读全文

摘要：First, ensure that the computer/sbc has WI-FI parts. install wpa_supplicant, edit /etc/wpa_supplicant/wpa_supplicant.conf, with ssid & psk. Then run w 阅读全文

摘要：when ping, specifying the length of the packet by: Actually default is -l 32, so if we omit the last option, the sent packets are the same. This packe 阅读全文

摘要：CURL usage.. -v, -m, -H, -I, -s, --connect-timeout, -x, -X GET|POST, -d, -T, -o. --retry, -u curl [options] [uri] 阅读全文

摘要：first get keepalived source from git: git clone https://github.com/acassen/keepalived then unzip and compile: ./configure make && make install install 阅读全文

摘要：tcp packet: tcp header: ip header: 阅读全文

摘要：journalctl -t ovs-vswitchd ovs-vsctl show ovs-ofctl show br0 set vlanid ovs-vsctl set port eth0 tag=100 阅读全文