鸟哥学习笔记---网络基本管理

 [root@szm ~]# netstat -tulnp

Active Internet connections (only servers)

Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name

tcp        0      0 0.0.0.0:51695               0.0.0.0:*                   LISTEN      1987/rpc.statd

tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN      1912/rpcbind

tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN      2224/sshd

tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      2300/master

tcp        0      0 :::46592                    :::*                        LISTEN      1987/rpc.statd

tcp        0      0 :::111                      :::*                        LISTEN      1912/rpcbind

tcp        0      0 :::22                       :::*                        LISTEN      2224/sshd

udp        0      0 0.0.0.0:38783               0.0.0.0:*                               1956/avahi-daemon:

udp        0      0 0.0.0.0:815                 0.0.0.0:*                               1912/rpcbind

udp        0      0 0.0.0.0:53296               0.0.0.0:*                               1987/rpc.statd

udp        0      0 0.0.0.0:68                  0.0.0.0:*                               1972/dhclient

udp        0      0 0.0.0.0:68                  0.0.0.0:*                               1975/dhclient

udp        0      0 0.0.0.0:5353                0.0.0.0:*                               1956/avahi-daemon:

udp        0      0 0.0.0.0:111                 0.0.0.0:*                               1912/rpcbind

udp        0      0 0.0.0.0:891                 0.0.0.0:*                               1987/rpc.statd

udp        0      0 :::52525                    :::*                                    1987/rpc.statd

udp        0      0 :::815                      :::*                                    1912/rpcbind

udp        0      0 :::111                      :::*                                    1912/rpcbind

 

 

[root@szm ~]# /etc/init.d/avahi-daemon stop

Shutting down Avahi daemon:                                [  OK  ]

 

[root@szm ~]# chkconfig avahi-daemon off

 

[root@szm ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE="eth0"

HWADDR="00:0C:29:24:C2:A5"

BOOTPROTO=dhcp

NM_CONTROLLED="yes" -----------网络控制

ONBOOT="yes"

 

[root@szm ~]# cat /etc/sysconfig/network

NETWORKING=yes

HOSTNAME=szm.test.com

 

[root@szm ~]# cat /etc/resolv.conf

# Generated by NetworkManager

domain localdomain

search localdomain test.com

nameserver 192.168.179.2

nameserver 172.16.2.1

nameserver 172.16.2.6

 

[root@szm ~]# cat /etc/hosts

192.168.179.139 szm.test.com    szm     # Added by NetworkManager

127.0.0.1       localhost.localdomain   localhost

::1     szm.test.com    szm     localhost6.localdomain6 localhost6

 

[root@szm ~]# dig www.baidu.com

 

; <<>> DiG 9.7.0-P2-RedHat-9.7.0-5.P2.el6 <<>> www.baidu.com

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22349

;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 4, ADDITIONAL: 4

 

;; QUESTION SECTION:

;www.baidu.com.                 IN      A

 

;; ANSWER SECTION:

www.baidu.com.          5       IN      CNAME   www.a.shifen.com.

www.a.shifen.com.       5       IN      A       61.135.169.105

www.a.shifen.com.       5       IN      A       61.135.169.125

 

;; AUTHORITY SECTION:

a.shifen.com.           5       IN      NS      ns5.a.shifen.com.

a.shifen.com.           5       IN      NS      ns7.a.shifen.com.

a.shifen.com.           5       IN      NS      ns9.a.shifen.com.

a.shifen.com.           5       IN      NS      ns4.a.shifen.com.

 

;; ADDITIONAL SECTION:

ns4.a.shifen.com.       5       IN      A       123.125.113.67

ns5.a.shifen.com.       5       IN      A       220.181.3.178

ns7.a.shifen.com.       5       IN      A       220.181.38.47

ns9.a.shifen.com.       5       IN      A       61.135.166.226

 

;; Query time: 11 msec

;; SERVER: 192.168.179.2#53(192.168.179.2)

;; WHEN: Wed Mar 20 22:43:59 2013

;; MSG SIZE  rcvd: 226

 

[root@szm ~]# iwconfig

lo        no wireless extensions.

 

eth0      no wireless extensions.

 

eth1      no wireless extensions.

 

[root@szm ~]# iwlist --help

Usage: iwlist [interface] scanning [essid NNN] [last]

              [interface] frequency

              [interface] channel

              [interface] bitrate

              [interface] rate

              [interface] encryption

              [interface] keys

              [interface] power

              [interface] txpower

              [interface] retry

              [interface] ap

              [interface] accesspoints

              [interface] peers

              [interface] event

              [interface] auth

              [interface] wpakeys

              [interface] genie

              [interface] modulation

 

 

 

       Flags  Possible flags include

              U (route is up)

              H (target is a host)

              G (use gateway)

              R (reinstate route for dynamic routing)

              D (dynamically installed by daemon or redirect)

              M (modified from routing daemon or redirect)

              A (installed by addrconf)

              C (cache entry)

              !  (reject route)

 

 

[root@szm ~]# route -n

Kernel IP routing table

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

172.16.128.0    0.0.0.0         255.255.255.0   U     1      0        0 eth1

0.0.0.0         172.16.128.254  0.0.0.0         UG    0      0        0 eth1

 

[root@szm ~]# route add -net 192.168.179.0 netmask 255.255.255.0 dev eth1

[root@szm ~]# route -n

Kernel IP routing table

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

192.168.179.0   0.0.0.0         255.255.255.0   U     0      0        0 eth1

172.16.128.0    0.0.0.0         255.255.255.0   U     1      0        0 eth1

0.0.0.0         172.16.128.254  0.0.0.0         UG    0      0        0 eth1

 

[root@szm ~]# route del -net 192.168.179.0 netmask 255.255.255.0 dev eth1

[root@szm ~]# route -n

Kernel IP routing table

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

172.16.128.0    0.0.0.0         255.255.255.0   U     1      0        0 eth1

0.0.0.0         172.16.128.254  0.0.0.0         UG    0      0        0 eth1

 

[root@szm ~]# route add default gw 192.168.1.254 -------不同子网，不行

SIOCADDRT: No such process

 

[root@szm ~]# route add default gw 172.16.128.154

[root@szm ~]# route -n

Kernel IP routing table

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

172.16.128.0    0.0.0.0         255.255.255.0   U     1      0        0 eth1

0.0.0.0         172.16.128.154  0.0.0.0         UG    0      0        0 eth1

0.0.0.0         172.16.128.254  0.0.0.0         UG    0      0        0 eth1

 

[root@szm ~]# ip link show

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN

    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 00:0c:29:24:c2:a5 brd ff:ff:ff:ff:ff:ff

3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000

    link/ether 00:0c:29:24:c2:af brd ff:ff:ff:ff:ff:ff

 

[root@szm ~]# ip link show eth1

3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000

    link/ether 00:0c:29:24:c2:af brd ff:ff:ff:ff:ff:ff

 

[root@szm ~]# ip -s link show eth0

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

    link/ether 00:0c:29:24:c2:a5 brd ff:ff:ff:ff:ff:ff

    RX: bytes  packets  errors  dropped overrun mcast

    415598     3291     0       0       0       0

    TX: bytes  packets  errors  dropped carrier collsns

    442311     2835     0       0       0       0

 

[root@szm ~]# ip link set eth1 down

[root@szm ~]# ip link set eth1 up

[root@szm ~]# ip link set eth1 mtu 1000

 

修改名字之前要Down网卡：

[root@szm ~]# ip link set eth1 name vbird

RTNETLINK answers: Device or resource busy

[root@szm ~]# ip link set eth1 down

[root@szm ~]# ip link set eth1 name vbird

 

设置网卡的MAC地址：

[root@szm ~]# ip link set vbird address 00:0c:29:23:c2:c1

[root@szm ~]# ip link show vbird

3: vbird: <BROADCAST,MULTICAST> mtu 1000 qdisc pfifo_fast state DOWN qlen 1000

    link/ether 00:0c:29:23:c2:c1 brd ff:ff:ff:ff:ff:ff

 

设置Ip地址：

[root@szm ~]# ip address show eth1

3: eth1: <BROADCAST,MULTICAST> mtu 1000 qdisc pfifo_fast state DOWN qlen 1000

    link/ether 00:0c:29:23:c2:c1 brd ff:ff:ff:ff:ff:ff

    inet 172.16.128.211/24 brd 172.16.128.255 scope global eth1

 

[root@szm ~]# ip address add 172.16.128.99/24 broadcast + dev eth1 label eth1:vbird

[root@szm ~]# ifconfig eth1

eth1      Link encap:Ethernet  HWaddr 00:0C:29:23:C2:C1

          inet addr:172.16.128.211  Bcast:172.16.128.255  Mask:255.255.255.0

          BROADCAST MULTICAST  MTU:1000  Metric:1

          RX packets:125594 errors:0 dropped:0 overruns:0 frame:0

          TX packets:3863 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:12181175 (11.6 MiB)  TX bytes:492270 (480.7 KiB)

          Interrupt:19 Base address:0x20a4

 

[root@szm ~]# ip address show eth1

3: eth1: <BROADCAST,MULTICAST> mtu 1000 qdisc pfifo_fast state DOWN qlen 1000

    link/ether 00:0c:29:23:c2:c1 brd ff:ff:ff:ff:ff:ff

    inet 172.16.128.211/24 brd 172.16.128.255 scope global eth1

    inet 172.16.128.99/24 brd 172.16.128.255 scope global secondary eth1:vbird

 

[root@szm ~]# ip address del 172.16.128.99/24 dev eth1

[root@szm ~]# ip address show eth1

3: eth1: <BROADCAST,MULTICAST> mtu 1000 qdisc pfifo_fast state DOWN qlen 1000

    link/ether 00:0c:29:23:c2:c1 brd ff:ff:ff:ff:ff:ff

    inet 172.16.128.211/24 brd 172.16.128.255 scope global eth1

 

添加路由：

[root@szm ~]# ip route show

192.168.179.0/24 dev eth0  proto kernel  scope link  src 192.168.179.139  metric 1

default via 192.168.179.2 dev eth0  proto static

 

[root@szm ~]# ip route add 192.168.180.0/24 dev eth0

[root@szm ~]# ip route show

192.168.179.0/24 dev eth0  proto kernel  scope link  src 192.168.179.139  metric 1

192.168.180.0/24 dev eth0  scope link

default via 192.168.179.2 dev eth0  proto static

 

 

[root@szm ~]# ip route add 192.168.190.0/24 via 192.168.179.2 dev eth0

[root@szm ~]# ip route show

192.168.179.0/24 dev eth0  proto kernel  scope link  src 192.168.179.139  metric 1

192.168.180.0/24 dev eth0  scope link

192.168.190.0/24 via 192.168.179.2 dev eth0

default via 192.168.179.2 dev eth0  proto static

 

 

 

 

[root@szm ~]# ip route del 192.168.180.0/24

[root@szm ~]# ip route del 192.168.190.0/24

[root@szm ~]# ip route show

192.168.179.0/24 dev eth0  proto kernel  scope link  src 192.168.179.139  metric 1

default via 192.168.179.2 dev eth0  proto static

 

DHCP获得IP地址：

[root@szm ~]# dhclient eth0

 

扫描地址主机：

[root@szm bin]# cat ping.sh

#!/bin/bash

for siteip in $(seq 1 254)

do

        site="172.16.128.${siteip}"

        ping -W1 -c1 $site &> /dev/null

        if [ "$?" == "0" ]; then

                echo "$site is up"

        else

                echo "$site is down"

        fi

done

 

如果你的主机与待检测主机并不在同一个网络内，那么TTL默认使用255，如果是同一个网络内，那么TTL则默认使用64

 

 [root@szm bin]# ping -c2 -s1000 -M do 172.16.128.254 （MTU有do和dont两个参数）

PING 172.16.128.254 (172.16.128.254) 1000(1028) bytes of data.

From 172.16.128.211 icmp_seq=1 Frag needed and DF set (mtu = 1000)

From 172.16.128.211 icmp_seq=1 Frag needed and DF set (mtu = 1000)

 

--- 172.16.128.254 ping statistics ---

0 packets transmitted, 0 received, +2 errors

 

 [root@szm bin]# traceroute -n tw.yahoo.com

traceroute to tw.yahoo.com (206.190.37.187), 30 hops max, 60 byte packets

 1  192.168.179.2  2.034 ms  1.819 ms  1.792 ms

 2  192.168.105.9  6.715 ms !N  6.630 ms !N  7.352 ms !N

traceroute默认使用的是UDP的超时等待，默认为5秒。对每个节点检测三次。

改用TCP做超时等待

[root@szm bin]# traceroute -n -T -w 1 tw.yahoo.com

traceroute to tw.yahoo.com (206.190.37.187), 30 hops max, 60 byte packets

 1  192.168.179.2  2.161 ms  1.396 ms  1.145 ms

 2  206.190.37.187  186.995 ms  187.765 ms  175.882 ms

 

[root@szm bin]# netstat -rn

Kernel IP routing table

Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface

192.168.179.0   0.0.0.0         255.255.255.0   U         0 0          0 eth0

172.16.128.0    0.0.0.0         255.255.255.0   U         0 0          0 eth1

0.0.0.0         192.168.179.2   0.0.0.0         UG        0 0          0 eth0

 

[root@szm bin]# netstat -an

 

[root@szm bin]# netstat -tln

Active Internet connections (only servers)

Proto Recv-Q Send-Q Local Address               Foreign Address             State

tcp        0      0 0.0.0.0:43373               0.0.0.0:*                   LISTEN

tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN

tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN

tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN

tcp        0      0 :::139                      :::*                        LISTEN

tcp        0      0 :::111                      :::*                        LISTEN

tcp        0      0 :::51412                    :::*                        LISTEN

tcp        0      0 :::22                       :::*                        LISTEN

tcp        0      0 :::445                      :::*                        LISTEN

 

Recv-Q:由非用户程序连接所复制而来的总bytes数 Send-Q:由远程主机发送而来的，但不具有ACK标志的总Bytes数，亦指主动连接SYN或其它标志的数据包所占的bytes数。

 

stat状态： 1.ESTABLISED：已经建立连接 2.SYN_SENT：发出主动连接（SYN标志）的连接数据包 3.SYN_RECV：接收到一个要求连接的主动连接数据包 4.FIN_WAIT1：该套接字服务（Socket）已中断，该连接正在断线当中 5.FIN_WAIT2：该连接已经挂断，但正在等待对方主机响应断线确认的数据包 6.TIME_WAIT：该连接已经挂断，但socket还在网络上等待结束 7.监听

 

[root@szm bin]# netstat -lutnp

[root@szm bin]# netstat -autnp

 

Client端是随机开放一个大于1024的Port进行连接，此外中有Root可以启动大于1024的Port    [root@szm bin]# cat /etc/services-----------存放Port与服务对应关系。

 

 

[root@szm bin]# host www.yahoo.com

www.yahoo.com is an alias for fd-fp3.wg1.b.yahoo.com.

fd-fp3.wg1.b.yahoo.com is an alias for ds-fp3.wg1.b.yahoo.com.

ds-fp3.wg1.b.yahoo.com is an alias for ds-fo-tw-sg.wg1.b.yahoo.com.

ds-fo-tw-sg.wg1.b.yahoo.com is an alias for ds-tw-fp3.wg1.b.yahoo.com.

ds-tw-fp3.wg1.b.yahoo.com has address 203.84.197.9

ds-tw-fp3.wg1.b.yahoo.com has address 203.84.197.25

ds-tw-fp3.wg1.b.yahoo.com has IPv6 address 2406:2000:f016:1fe::3000

ds-tw-fp3.wg1.b.yahoo.com has IPv6 address 2406:2000:f016:1fe::3001

指定服务器解析：

[root@szm bin]# host www.yahoo.com 172.16.2.1

Using domain server:

Name: 172.16.2.1

Address: 172.16.2.1#53

Aliases:

 

www.yahoo.com is an alias for fd-fp3.wg1.b.yahoo.com.

fd-fp3.wg1.b.yahoo.com is an alias for ds-fp3.wg1.b.yahoo.com.

ds-fp3.wg1.b.yahoo.com is an alias for ds-fo-tw-sg.wg1.b.yahoo.com.

ds-fo-tw-sg.wg1.b.yahoo.com is an alias for ds-tw-fp3.wg1.b.yahoo.com.

ds-tw-fp3.wg1.b.yahoo.com has address 203.84.197.25

ds-tw-fp3.wg1.b.yahoo.com has address 203.84.197.9

ds-tw-fp3.wg1.b.yahoo.com has IPv6 address 2406:2000:f016:1fe::3000

ds-tw-fp3.wg1.b.yahoo.com has IPv6 address 2406:2000:f016:1fe::3001

 

 

 

[root@szm bin]# nslookup -a www.yahoo.com

*** Invalid option: a

Server:         192.168.179.2

Address:        192.168.179.2#53

Non-authoritative answer:

www.yahoo.com   canonical name = fd-fp3.wg1.b.yahoo.com.

fd-fp3.wg1.b.yahoo.com  canonical name = ds-fp3.wg1.b.yahoo.com.

ds-fp3.wg1.b.yahoo.com  canonical name = ds-fo-tw-sg.wg1.b.yahoo.com.

ds-fo-tw-sg.wg1.b.yahoo.com     canonical name = ds-tw-fp3.wg1.b.yahoo.com.

Name:   ds-tw-fp3.wg1.b.yahoo.com

Address: 203.84.197.25

Name:   ds-tw-fp3.wg1.b.yahoo.com

Address: 203.84.197.9

 

 

[root@szm bin]# telnet localhost 110检测本地主机110这个Port是否正确启动

Trying 127.0.0.1...

telnet: connect to address 127.0.0.1: Connection refused

[root@szm bin]# telnet localhost 25检测

Trying 127.0.0.1...

Connected to localhost.

Escape character is '^]'.

220 szm.test.com ESMTP Postfix

ehlo localhost

250-szm.test.com

250-PIPELINING

250-SIZE 10240000

250-VRFY

250-ETRN

250-ENHANCEDSTATUSCODES

250-8BITMIME

250 DSN

quit

221 2.0.0 Bye

Connection closed by foreign host.

图形界面ftp:gftp

 

 

ftp常用命令:help,dir,cd,get file,mget file*,put file,delete file,mkdir,lcd /home,passive,binary,bye

 

[root@szm bin]# ftp 172.16.3.240 21

 

[root@szm bin]# lftp 172.16.3.240 -u kjdown,kjdown

 

[root@szm ~]# cat ./bin/lftp

open ftp.ksu.edu.tw

cd /pub/CentOS/

mget -c -d RPM-GPG*

bye

 

[root@szm ~]# lftp -f ./bin/lftp

 [root@szm ~]# cat ./bin/lftp.sh

lftp -c "open ftp.ksu.edu.tw

cd /pub/CentOS/

mget -c -d RPM-GPG*

bye"

[root@szm ~]# sh ./bin/lftp.sh

 

[root@szm ~]# links /usr/share/doc/HTML/index.html

 

[root@szm ~]# links http://www.kernel.org

h:history g:gotoURL d:downloadPage q:quit o:option,/.elinks/elinks.conf

 

下载网页：

[root@szm ~]# links -dump http://www.yahoo.com > yahoo.html

 

[root@szm ~]# tcpdump --help

tcpdump version 4.1-PRE-CVS_2010_08_20

libpcap version 1.0.0

Usage: tcpdump [-a AdD efIKlLnNOpqRStuUvxX] [ -B size ] [ -c count ]

                [ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]

                [ -i interface ] [ -M secret ] [ -r file ]

                [ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ]

                [ -y datalinktype ] [ -z command ] [ -Z user ]

                [ expression ]

-A:ASCII显示 -e:找二层包 -nn:不解析 -q：精简内容 -X：列出ASCII与hex内容对应 -i:接口 -w:保存包 -r:读包 -c:包数

 

[root@szm ~]# tcpdump -i eth0 -nn

 

[root@szm ~]# tcpdump -i eth0 -nn port 21

 

 

1： [root@szm ~]# tcpdump -i lo -nn

2： [root@szm ~]#  ssh localhost

 

1： [root@szm ~]# tcpdump -i lo port 21

 

[root@szm ~]# tcpdump -i lo -nn 'port 22 and src host 192.168.1.1'

 

开启20000端口监听：

[root@szm ~]# nc -l localhost 20000 &

 

连接2000端口：

[root@szm ~]# nc localhost 20000

kkk

dkfakd

eqreijkajfd^C

 

[1]+  Stopped                 nc -l localhost 20000

 

[root@szm ~]# fg

nc -l localhost 20000

 

kkk

dkfakd