Assign static IP addresses for egress traffic

This document shows you how to assign your own enterprise IP addresses, or static Google Cloud IP addresses, that Secure Web Proxy uses for egress traffic.

Before you begin

Complete the initial setup steps.
Ensure that you have a list of static IPv4 addresses reserved to use for Secure Web Proxy. If you want to reserve IP addresses in Google Cloud, see the gcloud compute addresses create command to create an address resource.
Verify that you have the Google Cloud CLI version 406.0.0 or later installed:
```
gcloud version | head -n1
```
If you have an earlier gcloud CLI version installed, update the version:
```
gcloud components update --version=406.0.0
```

Enable static IP addresses for Secure Web Proxy

Do the following:

Identify the Cloud Router name assigned during Secure Web Proxy provisioning:
```
gcloud compute routers list \
    --regions REGION \
    --filter="network:(NETWORK_NAME) AND name:(swg-autogen-router-*)" \
    --format="get(name)"
```
Replace the following:
- REGION: the region that the Cloud Router is deployed for Secure Web Proxy
- NETWORK_NAME: the name of your VPC network
The output is similar to the following:
```
swg-autogen-router-1
```

List the external automatically provisioned IP addresses assigned during Secure Web Proxy provisioning:

gcloud compute routers get-status ROUTER_NAME  \
    --regions=REGION

The output is similar to the following:

kind: compute#routerStatusResponse
result:
  natStatus:
  - autoAllocatedNatIps:
    - 34.144.80.46
    - 34.144.83.75
    - 34.144.88.111
    - 34.144.94.113
    minExtraNatIpsNeeded: 0
    name: swg-autogen-nat
    numVmEndpointsWithNatMappings: 3
  network: https://www.googleapis.com/compute/projects/PROJECT_NAME/global/networks/NETWORK_NAME

Update the Cloud NAT gateway to use your predefined IP range:
```
gcloud compute routers nats update swg-autogen-nat  \
    --router=ROUTER_NAME \
    --nat-external-ip-pool=IPv4_ADDRESSES... \
    --regions=REGION
```
Replace IPv4_ADDRESSES with the name of the external IPv4 address resource that you intend to use, separated by a comma (,).

Verify that your IP range is assigned to the Cloud NAT gateway:

gcloud compute routers nats describe swg-autogen-nat \
    --router=ROUTER_NAME  \
    --region=REGION

The output is similar to the following:

enableEndpointIndependentMapping: false
icmpIdleTimeoutSec: 30
logConfig:
  enable: false
  filter: ALL
name: swg-autogen-nat
natIpAllocateOption: MANUAL_ONLY
natIps:
- https://www.googleapis.com/compute/projects/PROJECT_NAME/regions/REGION/addresses/ADDRESS
sourceSubnetworkIpRangesToNat: ALL_SUBNETWORKS_ALL_IP_RANGES

Update the Cloud NAT gateway to use Dynamic Port Allocation (DPA) mode. DPA mode allows Secure Web Proxy to fully use the assigned IP addresses.
```
gcloud compute routers nats update swg-autogen-nat  \
    --router=ROUTER_NAME \
    --min-ports-per-vm=2046 \
    --max-ports-per-vm=4096 \
    --nat-enable-dynamic-port-allocation \
    --regions=REGION
```
For --min-ports-per-vm and --max-ports-per-vm flags, we recommend that you use values 2048 and 4096, respectively.

Use Metrics Explorer to monitor metrics data for the following and adjust DPA minimum and maximum values as needed:
- Cloud NAT Gateway - Port usage
- Cloud NAT Gateway - New connection count
- Cloud NAT Gateway - Open connections

Verify that your DPA is enabled and the minimum and maximum port values are set:

gcloud compute routers nats describe swg-autogen-nat \
    --router=ROUTER_NAME \
    --region=REGION

The output is similar to the following:

enableDynamicPortAllocation: true
enableEndpointIndependentMapping: false
endpointTypes:
- ENDPOINT_TYPE_SWG
logConfig:
  enable: true
  filter: ERRORS_ONLY
maxPortsPerVm: 4096
minPortsPerVm: 2048
name: swg-autogen-nat
natIpAllocateOption: MANUAL_ONLY
natIps:
- https://www.googleapis.com/compute/projects/PROJECT_NAME/regions/REGION/addresses/ADDRESS
sourceSubnetworkIpRangesToNat: ALL_SUBNETWORKS_ALL_IP_RANGES
type: PUBLIC

Assign static IP addresses for egress traffic

Before you begin

Enable static IP addresses for Secure Web Proxy

What's next?