0 Basic Learning Cloud computing and Big Data DBA cluster Architect "Linux systems \ Network services and Security Configuration January 7, 2015 Thursday"

Postfix1. Composition MUA: Mail user agent MTA: Message transfer agent MDA: Mail Distribution Agent 2. Protocol smtp: Simple Mail Transfer Protocol listening on Port 25th IMAP: Interactive mail Access Protocol 143 Port POP3: Electronic Post Office Transfer Protocol 110 Port 3. software postfix master configuration file:/etc/postfix/Main.cf4. local mail send and receive configuration Myhostname = mail.abc.comLocal mail server host name mydomain = abc.com--Local domain Name Myorigin = $mydomain--When I send an email, it shows the hostname or domain name mydestination = $myhostname, localhost. $mydomain, localhost, $mydomain--Receive messages from which names are sent 5. Start service postfix restart6. Send and receive mail-Mail command, installed by MAILX software to send mail: Mail [email protected]--Student user sent to abc.com subject:test--Theme this--Body ISATest. -End of Email: 1.mail -->n 1 root Fri Jan 8 10:50 22/540 "Test" & 1- -Enter message number to view the body contents of the corresponding message 2.mail -u user name--root user receives the location of the local user's mail message content/var/spool/Mail, there is a file with the same name as the user. 7. e-Mail Interoperability Experiment Environment: 6 Firewall and 7 firewall cleared off 6: Iptables-F service iptables STOP7: Systemctl stop firewalld 1) with DNS 1./etc/named.conf 2./etc/named. Rfc1912.zones 3. Data file Reverse solution: NS test.com.11 ptr abc.com.11 ptr mail.abc.com.10 ptr test.com.10 ptr ma il.test.com. 4./etc/resolv.conf 2) Postfixmyhostname = mail.abc.com -local mail server hostname mydomain = abc.com- local domain Name myorigin = $mydomain the hostname or domain name is displayed when I send the message mydestination = $myhostname, localhost. $mydomain, localhost, $mydomain- to receive messages from which names are sent inet_interfaces = All--and which hosts are monitored     

Firewall 1. function 2. General Syntax iptables-t table CMD chain Rule-matcher-J Target Table action chain rule matching perform action 3. Table: Actions to differentiate the execution of a packet 1) Filter table: For filtering packets 2NAT table: Used to modify the source and destination of the packet. 3Mangle table: User modified the lifetime of the packet and so on 4Raw table: Tracking mechanism Use- t to specify the table and, if omitted, to act on the filter Table 4 . The table contains chain chains that are used to differentiate the flow state of the packets. INPUT: Inbound Packet output: Outbound packet prerouting: Packet postrouting before route judgment: Packet forward after route judgment: After the first route is judged, before the last route is judged. 5 . Rules: is used to determine the specifics of the packet 6 . CMD 1 ) A for append I for insert 2 ) D for delete 3 ) L for List 4 ) F for empty 7 . Rule Matching- p protocol- s source- D destination-< Span>i Inbound Network interface- o Outbound network interface!  Reverse-- Dport Specify port number 8 . Target execution Action accept: Drop: Discard reject: Deny Dnat: Destination Address Translation Snat: Source address translation. Note: The matching order from top to bottom, when the matching requirements are met, will take precedence over the Operation Iptables state control. Saved in:/etc/sysconfig/ iptablesservice Iptables save-->  Save Iptablesiptables-restore </etc/sysconfig/ iptables Restores the last saved iptables State iptables-save >/etc/sysconfig/ iptables can also be saved in this way. EL7 firewall firewalld1. editing mode firewall-  Config graphical tool 2. Command line: firewall- cmd3 . Status control systemctl Restart Firewalld stop       

Kernel: Module 1. module: Provide some functions, need to load up, do not need to uninstall, can have a personalized control of the server. 2. View the modules that have been loaded lsmod3. Where the module is stored/lib/modules/2.6.32-431.el6.x86 _64/   end With. Ko 4. Load Module     insmod      modprobe5. Unload module    rmmod    modprobe-R6. View of the module information modinfo =================================== kernel parameters: 1. Location/proc/sys2. Change the way echo 1|0 > Kernel parameters file- - --temporary effective vim/etc/sysctl.conf--- permanent. Take. As a directory of the split Net.ipv4.ip_forward = 0 ==>/proc/  SYS directory under the net directory under the IPv4 directory, the Ip_forward parameter sets the parameter to not open.           

0 Basic Learning Cloud computing and Big Data DBA cluster Architect "Linux systems \ Network services and Security Configuration January 7, 2015 Thursday"