I've got a VM running Ubuntu 18.04 – it's all setup and running on a single public IP and has two interfaces – ens160
(public) & ens192
(private).
My interface ens160 is already fully configured. However, when I try and setup ens192
and apply the settings with netplan apply
, ens160
stops pinging externally.
ifconfig –
ens160: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 78.111.203.13 netmask 255.255.255.224 broadcast 78.111.203.31
inet6 fe80::250:56ff:feb2:ac74 prefixlen 64 scopeid 0x20<link>
ether 00:50:56:b2:ac:74 txqueuelen 1000 (Ethernet)
RX packets 8761053 bytes 3882588408 (3.8 GB)
RX errors 0 dropped 242551 overruns 0 frame 0
TX packets 10449256 bytes 4654699595 (4.6 GB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ens192: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 fe80::250:56ff:feb2:3d74 prefixlen 64 scopeid 0x20<link>
ether 00:50:56:b2:3d:74 txqueuelen 1000 (Ethernet)
RX packets 242552 bytes 14553120 (14.5 MB)
RX errors 0 dropped 227391 overruns 0 frame 0
TX packets 7256 bytes 2349506 (2.3 MB)
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 1000 (Local Loopback)
RX packets 9194 bytes 2309681 (2.3 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 9194 bytes 2309681 (2.3 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Here's the configuration file 50-cloud-init.yaml
I'm attempting below –
network:
ethernets:
ens160:
addresses:
- 78.111.203.13/27
gateway4: 78.111.203.1
nameservers:
addresses:
- 8.8.8.8
- 8.8.4.4
search: []
optional: true
ens192:
addresses:
- 10.0.203.13/27
gateway4: 10.0.203.1
optional: true
version: 2
As soon as I run netplan try
, I can no longer ping my external IP 78.111.203.13
until the timeout and the network resets itself. Interestingly though, I can still ping the external IP from other VM's within the network – I'm not sure if that means anything?
The newly configured internal IP also begins pinging within the network – what I'd expect.
I hope you can help!
Chris.
Best Answer
The problem is almost certainly related to you attempting to set a default gateway on the secondary interface.
It is important to always remember that the default gateway isn't really a property of an individual interface instead it is a route added to the route table. The 'default gateway' is the route that is used when no other more specific routes do not match a given destination. If you attempt to add two default gateways with the same metric, only one or the other will work.