Secondary IP (eth0:0) acts like main server IP
- by George Tasioulis
I have a CentOS server, configured with 4 consecutive IPs:
eth0 5.x.x.251
eth0:0 5.x.x.252
eth0:1 5.x.x.253
eth0:2 5.x.x.254
The problem is that all traffic goes out to the internet with eth0:0 (5.x.x.252) as the source IP, instead of eth0.
# curl ifconfig.me
5.x.x.252
How can I fix this, so that all traffic goes out via eth0, ie my main IP?
PS: My server is VPS running on a Xen dom0, the latter being configured in routed mode networking.
Thanks in advance!
Server configuration
# ifconfig
eth0 Link encap:Ethernet HWaddr 00:x:x:x:x:AE
inet addr:5.x.x.251 Bcast:5.x.x.255 Mask:255.255.255.255
inet6 addr: fe80::x:x:x:x/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:14675569 errors:0 dropped:0 overruns:0 frame:0
TX packets:9463227 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4122016502 (3.8 GiB) TX bytes:25959110751 (24.1 GiB)
Interrupt:23
eth0:0 Link encap:Ethernet HWaddr 00:x:x:x:x:AE
inet addr:5.x.x.252 Bcast:5.x.x.255 Mask:255.255.255.224
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:23
eth0:1 Link encap:Ethernet HWaddr 00:x:x:x:x:AE
inet addr:5.x.x.253 Bcast:5.x.x.255 Mask:255.255.255.224
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:23
eth0:2 Link encap:Ethernet HWaddr 00:x:x:x:x:AE
inet addr:5.x.x.254 Bcast:5.x.x.255 Mask:255.255.255.224
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:23
# cat /etc/hosts
127.0.0.1 localhost.localdomain localhost
5.x.x.251 [fqdn] [hostname]
# cat ifcfg-eth0
DEVICE=eth0
BOOTPROTO=static
ONBOOT=yes
IPADDR=5.x.x.251
NETMASK=255.255.255.224
SCOPE="peer 5.x.y.82"
# cat ifcfg-eth0:0
DEVICE=eth0:0
BOOTPROTO=static
ONBOOT=yes
IPADDR=5.x.x.252
NETMASK=255.255.255.224
# cat route-eth0
ADDRESS0=0.0.0.0
NETMASK0=0.0.0.0
GATEWAY0=5.x.y.82
# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
5.x.y.82 0.0.0.0 255.255.255.255 UH 0 0 0 eth0
5.x.x.224 0.0.0.0 255.255.255.224 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
0.0.0.0 5.x.y.82 0.0.0.0 UG 0 0 0 eth0