Our Cloud IP system enables you to create “floating” public IPv4 and IPv6 addresses and move them instantly between Cloud Servers, Cloud SQL instances and Load Balancers without any configuration on the resources themselves. To achieve this flexibility, we use Network Address Translation (NAT) to change the source or destination of the packets to the private IP address of the target resource.
NAT works very well for many use cases, but there are some scenarios where using NAT has some limitations. For example, if you map multiple Cloud IPs to the same Cloud Server, it’s not possible to determine which Cloud IP was the original destination. It’s also not possible to choose which Cloud IP address is used for outgoing connections. These are minor downsides usually, but for some advanced use cases it can make things difficult.
To address this (pun firmly intended), I’m pleased to announce a Routing Mode option for Cloud IPs which enables you to choose between the default NAT routing mode and a new “Route only” mode which routes packets directly to and from your Cloud Servers. This means you can map multiple Cloud IPs to a Cloud Server and have services listen individually on any one of them, have processes specify a particular IP for outgoing connections - in fact, anything you can do with a real native IP address on your server (because that’s what they are!)
Just switch the Cloud IP to
Route only mode, map it and add the address
to your server’s network configuration:
ubuntu@srv-xvgcv:~$ sudo ip addr add 18.104.22.168/32 dev ens3 ubuntu@srv-xvgcv:~$ ip addr show dev ens3 2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 02:24:19:f3:26:52 brd ff:ff:ff:ff:ff:ff inet 10.243.38.82/30 brd 10.243.38.83 scope global dynamic ens3 valid_lft 3051sec preferred_lft 3051sec inet 22.214.171.124/32 scope global ens3 valid_lft forever preferred_lft forever inet6 2a02:1348:17c:c994:24:19ff:fef3:2652/64 scope global dynamic mngtmpaddr noprefixroute valid_lft 3110sec preferred_lft 3110sec inet6 fe80::24:19ff:fef3:2652/64 scope link valid_lft forever preferred_lft forever
If you have any questions about the new Routing Mode get in touch and we’ll be happy to help.