> -----Original Message----- > From: Rock > Sent: Tuesday, July 23, 2013 17:46 > > QUESTION: > Why does my Centos 6.4 laptop keep wiping out my eth0 IP address? Googling https://www.google.com/search?q=rhel+6+network+configuration&oq=rhel+6+network https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/ht ml/Deployment_Guide/ch-Network_Interfaces.html > > SUMMARY: > a) I set the IP address of eth0 > b) Everything works fine for 2 to 5 minutes > c) Then, that eth0 IP address is (somehow?) wiped out I frustratingly > repeat that abc process (over and over and over again) What is the contents of /etc/sysconfig/network-scripts/ifcfg-eth0 ? > > BACKGROUND: > My home network has been working perfectly and there is no problem > with my home network, nor my wlan0 WiFi access from my Centos laptop > to that home broadband network. > > Inside the house, I never use the wired (eth0) NIC; but, I'm trying to > set up a wired/wireless connection outside the house and that is where > I'm running into this problem where Centos (automatically?) constantly > and repeatedly wipes out the IP address I set on eth0. > > I can easily (constantly) change the IP address of the eth0 NIC back > to what I want it to be; but that IP address only stays set for about > 2 to 5 minutes; and then it wipes itself out (again & again). > > Why? How do I stop this? > (All I want is for eth0 to *stay* at the IP address I set it to!) > > To give you more contextual detail, here's a typical sequence. > > SIMPLE BASELINE: > Wireless NIC (wlan0) is turned off using a hardware switch on the > outside of the laptop (so that only one NIC is in play). > > STARTING POINT: (eth0 has no IP address) $ ifconfig eth0 => eth0 Link > encap:Ethernet HWaddr A0:BE:C1:D8:E5:F1 > => inet6 addr: fe80::f2de:f1ff:fe38:8591/64 Scope:Link > => UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > => RX packets:3139 errors:0 dropped:0 overruns:0 frame:0 > => TX packets:3230 errors:0 dropped:0 overruns:0 carrier:0 > => collisions:0 txqueuelen:1000 > => RX bytes:2403080 (2.2 MiB) TX bytes:547895 (535.0 KiB) > => Interrupt:20 Memory:f2600000-f2620000 > > I EASILY CAN SET THE IP ADDRESS of eth0: > $ sudo ifconfig eth0 192.168.1.100 > $ ifconfig eth0 > => eth0 Link encap:Ethernet HWaddr A0:BE:C1:D8:E5:F1 > => inet addr:192.168.1.100 Bcast:192.168.1.255 > Mask:255.255.255.0 > => inet6 addr: fe80::f2de:f1ff:fe38:8591/64 Scope:Link > => UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > => etc. > > At this point, I can now connect a wire from the RJ45 port of the > laptop, to the device (which happens to be a radio set to > 192.168.1.20): > > $ ping 192.168.1.20 > => PING 192.168.1.20 (192.168.1.20) 56(84) bytes of data. > => 64 bytes from 192.168.1.20: icmp_seq=1 ttl=64 time=1.38 ms => 64 > bytes from 192.168.1.20: icmp_seq=2 ttl=64 time=0.339 ms => 64 bytes > from 192.168.1.20: icmp_seq=3 ttl=64 > time=0.255 ms ^C => --- 192.168.1.20 ping statistics --- => 3 packets > transmitted, 3 received, 0% packet loss, time 2954ms => rtt > min/avg/max/mdev = 0.255/0.660/1.388/0.516 ms > > I can even easily connect via port 80 (using Firefox on the > laptop) to this device, e.g., $ firefox http://192.168.1.20 > > In fact, time and time (and time) again, everything works just fine, > for about 2 to 5 minutes, until, invariably, I lose all connectivity! > > What seems to happen is that CentOS wipes out my IP address that I had > set for eth0. So, I lose all connectivity. > > $ ifconfig eth0 > => eth0 Link encap:Ethernet HWaddr A0:BE:C1:D8:E5:F1 > => inet6 addr: fe80::f2de:f1ff:fe38:8591/64 Scope:Link > => UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > > I can repeat the process, and everything works again, for about 2 to > 5 minutes. Then I lose my eth0 IP address again. > > WHAT I WANT: > When I set eth0 to an IP address, I want eth0 to *stay* at that IP > address! > > My question: > Q: Why does setting an eth0 IP address only last about 5 minutes on > Centos? > What am I doing wrong? > What can I do to *keep* the IP address on eth0 that I set for eth0? > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- - - - Jason Pyeron PD Inc. http://www.pdinc.us - - Principal Consultant 10 West 24th Street #100 - - +1 (443) 269-1555 x333 Baltimore, Maryland 21218 - - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- This message is copyright PD Inc, subject to license 20080407P00.