Hi folks,
I have a server at Soyoustart.com (which is a brand of OVH). I run CentOS 6.7 and have problems with network configuration.
I want to add a second public ip (failover ip) to the server and did follow the instructions in the CentOS-section of http://hilfe.ovh.de/AdministrationIpAliasHinzufuegen
After executing the required steps I'm not able to reach the host via the second ip from an external host. I tried it with ping and with ssh commands.
Here the content of the config files (I anonymized the server ip with xx.xx.xx.xx and the failover ip with yy.yy.yy.yy):
$ cat /etc/sysconfig/network NETWORKING=yes HOSTNAME=<name-of-my-host> NOZEROCONF=true GATEWAY=xx.xx.xx.254
$ cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 BOOTPROTO=static IPADDR=xx.xx.xx.xx NETMASK=255.255.255.0 ONBOOT=yes GATEWAY=xx.xx.xx.254
$ cat /etc/sysconfig/network-scripts/ifcfg-eth0:0 DEVICE=eth0:0 BOOTPROTO=static IPADDR=yy.yy.yy.yy NETMASK=255.255.255.255 ONBOOT=yes
When I restart the network I get a message (two times) saying "RTNETLINK answers: Operation not supported".
$ service network restart Schnittstelle eth0 beenden: [ OK ] Loopback-Schnittstelle beenden: [ OK ] Loopback-Schnittstelle hochfahren: [ OK ] Schnittstelle eth0 hochfahren: Determining if ip address xx.xx.xx.xx is already in use for device eth0... RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported [ OK ]
I can see two interfaces eth0 and eth0:0
$ LANG="" ifconfig eth0 Link encap:Ethernet HWaddr ..:..:..:..:..:.. inet addr:xx.xx.xx.xx Bcast:xx.xx.xx.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:11122 errors:0 dropped:0 overruns:0 frame:0 TX packets:14371 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1362900 (1.2 MiB) TX bytes:3462327 (3.3 MiB) Interrupt:20 Memory:fe500000-fe520000
eth0:0 Link encap:Ethernet HWaddr ..:..:..:..:..:.. inet addr:yy.yy.yy.yy Bcast:yy.yy.yy.yy Mask:255.255.255.255 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:20 Memory:fe500000-fe520000
lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:3096 errors:0 dropped:0 overruns:0 frame:0 TX packets:3096 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:274948 (268.5 KiB) TX bytes:274948 (268.5 KiB)
I'm able to reach the host from another host (outside OVH network) via xx.xx.xx.xx (I use ping and ssh), but not via yy.yy.yy.yy.
Just to be sure that there isn't an issue with the firewall I did "service iptables stop" and ran the "ping" and "ssh" commands again with the same result. For ip xx.xx.xx.xx it works, but not for yy.yy.yy.yy.
Not sure if this is important, just in case it matters, some additional information:
IPv6 is disabled by kernel parameter "ipv6.disable=1" in /etc/grub.conf
The two mac addresses I see for eth0 and eth0:0 with the "ifconfig" command are the same. In the OVH/Soyoustart.com GUI I created a virtual mac for the failover ip, I'm not sure if that virtual mac should come into play somewhere?
$ uname -a Linux <name-of-my-host> 2.6.32-573.12.1.el6.x86_64 #1 SMP Tue Dec 15 21:19:08 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
$ LANG="" route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface xx.xx.xx.0 * 255.255.255.0 U 0 0 0 eth0 default vss-gw-6k.fr.eu 0.0.0.0 UG 0 0 0 eth0
Why is yy.yy.yy.yy not reachable from outside? What am I doing wrong or what can I do to narrow down the problem?
Regards,
Meikel