diff --git a/site/using-weave/awsvpc.md b/site/using-weave/awsvpc.md index 92a727ff..94a4a47e 100644 --- a/site/using-weave/awsvpc.md +++ b/site/using-weave/awsvpc.md @@ -3,25 +3,25 @@ title: Using IP Routing on an Amazon Web Services Virtual Private Cloud menu_order: 110 --- -If you are running your container infrastructure entirely within -Amazon Web Services (AWS) Elastic Compute Cloud (EC2), then you can -choose AWS-VPC mode to connect your containers without any overlay, so -they can operate very close to the full speed of the underlying -network. +If your container infrastructure is running entirely within Amazon Web Services (AWS) +Elastic Compute Cloud (EC2), then you can enable AWS-VPC mode with Weave Net. In AWS-VPC mode, +containers are networked without using an overlay and allows network speeds +close to that of the underlying network. -In this mode, Weave Net still manages IP addresses and connects -containers to the network, but instead of wrapping up each packet and +With AWS-VPC enabled, Weave Net manages IP addresses and connects +containers to the network as usual, but instead of wrapping each packet and sending it to its destination, Weave Net instructs the AWS network -router which ranges of container IP addresses live on which instance. +router with the ranges of container IP addresses and the instances +on which they live. ![Weave Net AWS-VPC Mode](weave-net-awsvpc-1007x438.png) -###Configuring your EC2 instances to use Weave AWS-VPC mode +###Configuring EC2 Instances to use Weave AWS-VPC Mode -First, your AWS instances need to be given access to change the route -table. Give them an IAM Role which has this access; if you have an -existing role then extend it or create a new one with a policy -allowing the necessary actions: +First, your AWS instances need to be given write access to the route +table. Give them an IAM Role which has the following access, or if you have an +existing role, then extend it or create a new role with a policy +that allows the necessary actions: ``` { @@ -44,46 +44,47 @@ allowing the necessary actions: } ``` -Your Security Group must allow network traffic between instances: you -must open TCP port 6783 which Weave Net uses to manage the network, -and you must allow any ports which your own containers use. Remember: -there is no network overlay in this mode so IP packets with container +Secondly, your Security Group must allow network traffic between instances. +You must open TCP port 6783 which is the port that Weave Net uses to manage the network and also +allow any ports which your own containers use. + +>>**Remember:** There is no network overlay in this mode, and so, IP packets with container addresses will flow over the AWS network unmodified. -Also, you must disable the "Source/Destination check" on each machine, -because Weave will be operating with IP addresses outside of the range -allocated by Amazon. +Finally, since Weave will be operating with IP addresses outside of the +range allocated by Amazon, you must disable "Source/Destination check" on each machine. -###Using AWS-VPC mode +###Using AWS-VPC Mode -Launch Weave Net, adding the `--awsvpc` flag: +Launch Weave Net with the `--awsvpc` flag: $ weave launch --awsvpc [other hosts] -You still need to supply the names or IP addresses of other hosts in + >>**Note:** You will still need to supply the names or IP addresses of other hosts in your cluster. -###Limitations +###Present Limitations - AWS-VPC mode does not inter-operate with other Weave Net modes; it is all or nothing. In this mode, all hosts in a cluster must be AWS - instances. We hope to ease this limitation in future. + instances. (We hope to ease this limitation in future.) - The AWS network does not support multicast. - The number of hosts in a cluster is limited by the maximum size of your AWS route table. This is limited to 50 entries though you can request an increase to 100 by contacting Amazon. -- All your containers must be on the same network, with no subnet - isolation. We hope to ease this limitation in future. +- All of your containers must be on the same network, with no subnet + isolation. (We hope to ease this limitation in future.) ###Packet size (MTU) The Maximum Transmission Unit, or MTU, is the technical term for the limit on how big a single packet can be on the network. Weave Net -defaults to 1410 bytes which works across almost all networks, but you -can set a larger size for better performance. +defaults to 1410 bytes. This default works across almost all networks, but for better +performance you can set it to a larger MTU size. -The AWS network supports packets of 9000 bytes, so in AWS-VPC mode you -can run: +The AWS network supports packets of up to 9000 bytes. + +In AWS-VPC mode you can run the following: $ WEAVE_MTU=9000 weave launch --awsvpc host2 host3