Hope you are all well.
I've got a Newly built Linux CentOS 3.10.0-862.9.1.el7.x86_64 system running in a vmware environment.
I've got a Draytek 3900 router doing natting from 3 different WAN`s over 3 Different Vlan to the same CentOS server (Urghhh)
The nattings works perfectly fine and was confirmed by a Draytek tech. And ive confirmed that the rules are working using Wireshark.
So whats happening is that the CentOS server is only replying using one nic, and i cannot access (For example) ssh from the other two NICs.
But if i disable the "Working" nic, then one of the other nics takes over the connection and the 2nd "NAT" works.
I suspect that the OS is accepting traffic from all NIC, but not replying back over that same nic. Traffic seems to be passing through a different nic on its return path.
I would like to get the server to reply back to the same Default gateway instead of a different gateway.
This is true for any port i try to test, so its not just ssh (Which listens on 0.0.0.0)
I have assigned 3 NIC`s to the server. Each nic is connected to a different Vlan (Vlan 110,111,112)
Vlan 110 = 192.168.110.0/24
Vlan 111 = 192.168.111.0/24
Vlan 112 = 192.168.112.0/24
My CentOS is configured with the following Settings
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
NAME="ens192 192.168.111.240"
UUID=e6d31966-1a84-4674-a562-037895080936
DEVICE=ens192
ONBOOT=yes
MASK="255.255.255.0"
IPV6INIT=no
IPADDR=192.168.111.240
PREFIX=24
GATEWAY=192.168.111.254
DNS1=8.8.8.8
HWADDR=00:0C:29:7C:8B:AD
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
IPADDR=192.168.112.240
PREFIX=24
GATEWAY=192.168.112.254
DNS1=8.8.8.8
DEFROUTE=no
IPV4_FAILURE_FATAL=no
NAME=192.168.111.240
UUID=186c162e-1abc-3574-8be3-3a4a5409658f
ONBOOT=yes
AUTOCONNECT_PRIORITY=-999
Here is my routing tableHWADDR=00:0C:29:7C:8B:B7
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
IPADDR=192.168.110.240
PREFIX=24
GATEWAY=192.168.110.254
DNS1=8.8.8.8
DEFROUTE=no
IPV4_FAILURE_FATAL=no
NAME="Wired connection 2"
UUID=b234a56d-87b0-32fc-a209-49f994a8bbef
ONBOOT=yes
AUTOCONNECT_PRIORITY=-999
route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.112.254 0.0.0.0 UG 103 0 0 ens224
0.0.0.0 192.168.111.254 0.0.0.0 UG 105 0 0 ens192
192.168.110.0 192.168.110.254 255.255.255.0 UG 0 0 0 ens256
192.168.110.0 0.0.0.0 255.255.255.0 U 104 0 0 ens256
192.168.111.0 0.0.0.0 255.255.255.0 U 105 0 0 ens192
192.168.112.0 192.168.112.254 255.255.255.0 UG 0 0 0 ens224
192.168.112.0 0.0.0.0 255.255.255.0 U 103 0 0 ens224
Please let me know if i have missed any information.ip route list
default via 192.168.112.254 dev ens224 proto static metric 103
default via 192.168.111.254 dev ens192 proto static metric 105
192.168.110.0/24 via 192.168.110.254 dev ens256
192.168.110.0/24 dev ens256 proto kernel scope link src 192.168.110.240 metric 104
192.168.111.0/24 dev ens192 proto kernel scope link src 192.168.111.240 metric 105
192.168.112.0/24 via 192.168.112.254 dev ens224
192.168.112.0/24 dev ens224 proto kernel scope link src 192.168.112.240 metric 103
Hope you guys can help;. Have a great day!