On Feb 20, 2017 2:42 PM, "Rommel Rodriguez Toirac" <rommelrt at nauta.cu> wrote: Hi; I have a CentOS 6.8 x86_64 server where just run Oracle 11g 64 bit data base server. Is happen that sometimes it loose all connections (no ping, I can not access via ssh, no TNSping of Oracle server have success). When this happend I make ping from this server to some IP address of my network and then everything work fine again. I check logs looking for some mistake or problem in the network device, but I do not find anything or maybe I not looking where must be. I check that from a workstation (Windows XP or Windows 7 or Windows 10) when I make ping to the server, after ~ 8 seconds in get answer and always the first one is loose. If you try again ping, everything work fine (no answers are loose) C:\Users\administrator>ping pgtm.gtm.gob.cu Haciendo ping a pgtm.gtm.gob.cu [192.168.41.4] con 32 bytes de datos: Tiempo de espera agotado para esta solicitud. Respuesta desde 192.168.41.4: bytes=32 tiempo<1m TTL=64 Respuesta desde 192.168.41.4: bytes=32 tiempo<1m TTL=64 Respuesta desde 192.168.41.4: bytes=32 tiempo<1m TTL=64 Estad?sticas de ping para 192.168.41.4: Paquetes: enviados = 4, recibidos = 3, perdidos = 1 (25% perdidos), Tiempos aproximados de ida y vuelta en milisegundos: M?nimo = 0ms, M?ximo = 0ms, Media = 0ms This are some of the configs related with networks [root at pgtm ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 TYPE=Ethernet UUID=11dcddd4-6530-457a-8d3e-01a8339fb113 ONBOOT=yes NM_CONTROLLED=yes BOOTPROTO=none HWADDR=6C:92:BF:26:C7:02 IPADDR=192.168.41.4 PREFIX=24 GATEWAY=192.168.41.1 DNS1=192.168.41.17 DOMAIN=gtm.gob.cu DEFROUTE=yes IPV4_FAILURE_FATAL=yes IPV6INIT=no NAME="System eth0" L I noticed from your ipcfg-eth0 file, the address 192.168.41.1 is assigned to eth0. When you typed the command "ifconfig", that same address was assigned to eth1. Try changing the name of this file to ipcfg-eth1 and restart networkmanager. As was stated earlier, check your gateway and see what other devices could be using that address. Put a block on that unknown MAC address if you can. cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.41.4 pgtm pgtm.gtm.gob.cu [root at pgtm ~]# cat /etc/resolv.conf # Generated by NetworkManager search gtm.gob.cu nameserver 192.168.41.17 [root at pgtm mail]# cat /etc/sysconfig/network NETWORKING=yes HOSTNAME=pgtm.gtm.gob.cu GATEWAY=192.168.41.1 Someone that happend something like this, or some place for where keep looking to try to fix this loose of conection? Thank and sorry for my horryble English. Rommel Rodriguez Toirac rommelrt at nauta.cu _______________________________________________ CentOS mailing list CentOS at centos.org https://lists.centos.org/mailman/listinfo/centos