Server not accessible on eth1 (additional network interface) CentOS 7 on AWS EC2

I have created a CentOS 7 instance on EC2, installed my required application-ware, assigned 1 Elastic IP to default network interface (eth0) and it is all accessible.

Now I created another Network Interface, assigned an Elastic IP to that and then attach the ENI afterwards to the instance. Now, the instance isn’t reachable on the eth1 (new additional network interface).

I have tried various approaches found on google creating ifcfg-eth1 in /etc/sysconfig/network-scripts but with no luck.

For help, this is the output from ifconfig -a (IPs masked):

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9001
        inet 1XX.3XX.2XX.4XX  netmask 255.255.240.0  broadcast 1XX.3XX.2XX.4XX
        inet6 fe80::2e:a1ff:fe01:c763  prefixlen 64  scopeid 0x20<link>
        ether 02:2e:a1:01:c7:63  txqueuelen 1000  (Ethernet)
        RX packets 219  bytes 28188 (27.5 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 284  bytes 31055 (30.3 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth1: flags=4098<BROADCAST,MULTICAST>  mtu 1500
        ether 02:78:73:34:66:35  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 0  (Local Loopback)
        RX packets 23  bytes 4968 (4.8 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 23  bytes 4968 (4.8 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

And this is from ip addr:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9001 qdisc pfifo_fast state UP qlen 1000
    link/ether 02:2e:a1:01:c7:63 brd ff:ff:ff:ff:ff:ff
    inet 1XX.3XX.2XX.4XX/20 brd 1XX.3XX.2XX.4XX scope global dynamic eth0
       valid_lft 3404sec preferred_lft 3404sec
    inet6 fe80::2e:a1ff:fe01:c763/64 scope link
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 02:78:73:34:66:35 brd ff:ff:ff:ff:ff:ff

My /etc/sysconfig/network-scripts/ifcfg-eth0 file has these contents:

DEVICE="eth0"
BOOTPROTO="dhcp"
ONBOOT="yes"
TYPE="Ethernet"
USERCTL="yes"
PEERDNS="yes"
IPV6INIT="no"
PERSISTENT_DHCLIENT="1"

Related:

Leave a Reply