LinuC（Linux技術者認定資格）＆リナックスサーバ構築設定事例

[root@A]# dmesg | grep eth
eth0: registered as PCnet/PCI II 79C970A
eth0: link up
eth0: no IPv6 routers present

[root@A]# lspci
02:01.0 Ethernet controller: Advanced Micro Devices [AMD] 79c970 [PCnet32 LANCE] (rev 10)

[root@A]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0C:29:C9:99:4C
          inet addr:192.168.0.55  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fec9:994c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3702 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2489 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:360938 (352.4 KiB)  TX bytes:301017 (293.9 KiB)
          Interrupt:75 Base address:0x2000

[root@A]# ifconfig eth0:0 192.168.0.56 netmask 255.255.255.0 up

[root@A]# ifconfig eth0:0
eth0:0    Link encap:Ethernet  HWaddr 00:0C:29:C9:99:4C
          inet addr:192.168.0.56  Bcast:192.168.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:75 Base address:0x2000

[root@A]# arp
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.0.21             ether   E0:CB:4E:11:FC:EC   C                     eth0
buffalo.setup            ether   00:0D:0B:B6:0A:B6   C                     eth0

[root@A]# arp -n
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.0.21             ether   E0:CB:4E:11:FC:EC   C                     eth0
192.168.0.1              ether   00:0D:0B:B6:0A:B6   C                     eth0

[root@A]# traceroute sentos5
traceroute to sentos5 (127.0.0.1), 30 hops max, 40 byte packets
 1  sentos5.localdomain (127.0.0.1)  0.019 ms  0.011 ms  0.009 ms

[root@A]# traceroute -n sentos5
traceroute to sentos5 (127.0.0.1), 30 hops max, 40 byte packets
 1  127.0.0.1  0.018 ms  0.009 ms  0.013 ms

[root@A]# tcpdump -i eth0
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
22:50:53.721877 IP 192.168.0.55.ssh > 192.168.0.21.52146: P 2187861119:2187861235(116) ack 2768986704 win 7504
22:50:53.722047 IP 192.168.0.55.ssh > 192.168.0.21.52146: P 116:232(116) ack 1 win 7504

[root@A]# tcpdump -nli eth0 port 53
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
22:52:56.040693 IP 192.168.0.21.53094 > 192.168.0.1.domain:  17340+ A? www.nicovideo.jp. (34)
22:52:56.073466 IP 192.168.0.1.domain > 192.168.0.21.53094:  17340 1/2/1 A 202.248.110.243 (116)

[root@A]# netstat -l
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State
tcp        0      0 sentos5.localdomain:2208    *:*                         LISTEN
tcp        0      0 *:nfs                       *:*                         LISTEN

[root@A]# netstat -i
Kernel Interface table
Iface       MTU Met    RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0       1500   0     8091      0      0      0     8978      0      0      0 BMRU
lo        16436   0     3180      0      0      0     3180      0      0      0 LRU

[root@A]# netstat -r
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
192.168.0.0     buffalo.setup   255.255.255.0   UG        0 0          0 eth0
192.168.0.0     *               255.255.255.0   U         0 0          0 eth0
default         buffalo.setup   0.0.0.0         UG        0 0          0 eth0

[root@A]# nc 192.168.0.55 25
220 sentos5.localdomain ESMTP Postfix

[root@A]# nc -vz 192.168.0.55 1-1000
nc: connect to 192.168.0.55 port 1 (tcp) failed: Connection refused
nc: connect to 192.168.0.55 port 2 (tcp) failed: Connection refused

[root@A]# nc -vzu 192.168.0.55 1-1000
Connection to 192.168.0.55 111 port [udp/sunrpc] succeeded!
Connection to 192.168.0.55 161 port [udp/snmp] succeeded!

[root@A]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.0.0     *               255.255.255.0   U     0      0        0 eth0

[root@A]# route add default gw 192.168.0.1

[root@A]# route add -net 192.168.0.0 netmask 255.255.255.0 gw 192.168.0.1

[root@A]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.0.0     buffalo.setup   255.255.255.0   UG    0      0        0 eth0
192.168.0.0     *               255.255.255.0   U     0      0        0 eth0
default         buffalo.setup   0.0.0.0         UG    0      0        0 eth0

[root@A]# ip route show
192.168.0.0/24 via 192.168.0.1 dev eth0
192.168.0.0/24 dev eth0  proto kernel  scope link  src 192.168.0.55
default via 192.168.0.1 dev eth0

[root@A]# iwconfig
lo        no wireless extensions.
eth0      no wireless extensions.
sit0      no wireless extensions.

[root@A]# iwconfig wlan0
wlan0     No such device

[root@A]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1               sentos5.localdomain sentos5 localhost.localdomain localhost
::1             localhost6.localdomain6 localhost6

[root@A]# cat /etc/nsswitch.conf
passwd:     files ldap
shadow:     files ldap
group:      files ldap
hosts:      files ldap dns

[root@A]# cat /etc/resolv.conf
nameserver 192.168.0.1

[root@A]# cat /etc/sysconfig/network
NETWORKING=yes
NETWORKING_IPV6=no
HOSTNAME=sentos5.localdomain

[root@A]# ls -l /etc/sysconfig/network-scripts/*
-rw-r--r-- 3 root root   193    羌  2010 /etc/sysconfig/network-scripts/ifcfg-eth0

[root@A]# cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=none
ONBOOT=yes
HWADDR=00:0c:29:c9:99:4c
NETMASK=255.255.255.0
IPADDR=192.168.0.55
GATEWAY=192.168.0.1
TYPE=Ethernet

[root@A]# cat /etc/hosts.allow

[root@A]# cat /etc/hosts.deny

[root@A]# tracepath 192.168.0.55
 1:  192.168.0.55 (192.168.0.55)                            0.079ms pmtu 16436
 1:  192.168.0.55 (192.168.0.55)                            0.021ms reached
     Resume: pmtu 16436 hops 1 back 1

[root@A]# cat /etc/issue
CentOS release 5.3 (Final)
Kernel \r on an \m

[root@A]# cat /etc/issue.net
CentOS release 5.3 (Final)
Kernel \r on an \m

[root@A]# cat /etc/motd

[root@A]# wall "Test Message !"
Broadcast message from root (pts/2) (Wed Jan  5 23:28:43 2011):
Test Message !

[root@A]# shutdown -k now "Test Message!!!"
Broadcast message from root (pts/2) (Wed Jan  5 23:29:23 2011):
Test Message!!!
The system is going down to maintenance mode NOW!
Shutdown cancelled.