Linux – Multiple ip to single interface

ioiplinuxnetworking

i'm using openstack, but i think this is a more general problem. Actually i've a dedicated which comes with 1 ip address, i bought another one, and added using openstack's nova-manage cli.

So now this is what i get

$ ip addr
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:30:48:fc:4c:92 brd ff:ff:ff:ff:ff:ff
    inet 188.165.x.x/24 brd 188.165.225.255 scope global eth0
    inet 94.23.x.x/32 scope global eth0
    inet6 fe80::230:48ff:fefc:4c92/64 scope link
    valid_lft forever preferred_lft forever

so it seems that both ip are binded to eth0, the problems is that i don't receive packets with destination set to 94.23.x.x, when i run tcpdump -i eth0 i see packets to both ip, when i run tcpdump -p -i eth0, so not in promiscous mode, i see packets to only the first ip, so dnat and what i need won't work.

If i try to ping 94.23.x.x on the host works fine, from outside gives timeout.

Any idea?

Best Regards

EDIT:

$ ip route
default via 188.165.x.254 dev eth0  metric 100 
188.165.x.0/24 dev eth0  proto kernel  scope link  src 188.165.x.x 
192.168.3.0/24 dev br100  proto kernel  scope link  src 192.168.3.1 
192.168.4.32/27 dev br100  proto kernel  scope link  src 192.168.4.33 
192.168.122.0/24 dev virbr0  proto kernel  scope link  src 192.168.122.1

Best Answer

Can you check, what is destination MAC address on packets you receiving in tcpdump in promiscuous mode?

If it's destination MAC is not correct: 00:30:48:fc:4c:92 - you have an IP conflict and should contact your provider.

If it's correct - you have problems on your side, e.g. wrong NIC, ip, kernel settings, maybe incorrect netmask or routing problems.

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