How to Configure Routes

This guide shows you how to add, update, and manage routing rules for Arctic services. Routes determine which traffic flows through a service based on source and destination CIDR blocks.

Before You Start

Ensure you have:

• An existing service (see Create a Service)
• The service ID
• Knowledge of the networks you want to route

Add a Route

Basic Route

Add a route matching specific source and destination networks:

arctic routes add --service SERVICE_ID \
  --source-cidr 10.0.0.0/8 \
  --dest-cidr 192.168.100.0/24 \
  --priority 100

Destination-Only Route

Route all traffic to a specific destination regardless of source:

arctic routes add --service SERVICE_ID \
  --dest-cidr 192.168.100.0/24 \
  --priority 100

Source-Only Route

Route all traffic from a specific source regardless of destination:

arctic routes add --service SERVICE_ID \
  --source-cidr 10.0.0.0/8 \
  --priority 100

Understanding Priority

Routes are evaluated by specificity and priority:

1. Most specific match wins: A route with /24 CIDR is more specific than /16
2. Higher priority wins: When specificity is equal, higher priority value wins

Example ordering (most preferred first):

List Routes

View all routes for a service:

arctic routes list --service SERVICE_ID

Update a Route

Modify an existing route's priority or CIDR:

arctic routes update --service SERVICE_ID --route ROUTE_ID \
  --priority 200

You can also update the CIDRs:

arctic routes update --service SERVICE_ID --route ROUTE_ID \
  --source-cidr 10.1.0.0/16 \
  --dest-cidr 192.168.200.0/24

Delete a Route

Remove a route from a service:

arctic routes delete --service SERVICE_ID --route ROUTE_ID

# Use --yes to skip confirmation:
arctic routes delete --service SERVICE_ID --route ROUTE_ID --yes

Common Routing Patterns

Route All Traffic to a Service

Route everything from one network to another:

arctic routes add --service SERVICE_ID \
  --source-cidr 10.0.0.0/8 \
  --dest-cidr 0.0.0.0/0 \
  --priority 100

Multiple Routes for Different Subnets

Add routes for different destination subnets:

# Route to subnet A
arctic routes add --service SERVICE_ID \
  --dest-cidr 192.168.100.0/24 \
  --priority 100

# Route to subnet B
arctic routes add --service SERVICE_ID \
  --dest-cidr 192.168.200.0/24 \
  --priority 100

Override with Higher Priority

Add a more specific route that overrides a general one:

# General route (lower priority)
arctic routes add --service SERVICE_ID \
  --source-cidr 10.0.0.0/8 \
  --dest-cidr 192.168.0.0/16 \
  --priority 100

# Specific override (higher priority)
arctic routes add --service SERVICE_ID \
  --source-cidr 10.1.0.0/16 \
  --dest-cidr 192.168.100.0/24 \
  --priority 200

Troubleshooting

Routes Not Taking Effect

If traffic is not being routed as expected:

1. Trigger a config sync: arctic cluster sync
2. Verify NFTables rules: nft list ruleset | grep arctic
3. Check the generated config: cat /opt/tillered/pegasus/config.json

Invalid CIDR Notation

Ensure CIDRs are valid:

• Use slash notation: 10.0.0.0/8 not 10.0.0.0
• Network address must match the mask: 10.0.0.0/8 not 10.1.2.3/8

Route Not Found

If a route ID is not found:

1. List routes to verify: arctic routes list --service SERVICE_ID
2. Ensure you are using the correct service ID

Related

• Create a Service
• Delete a Service
• routes CLI Reference
• Routing Concepts