azure-expressroute

# Azure ExpressRoute Skill

This skill provides expert guidance for Azure ExpressRoute. Covers troubleshooting, best practices, decision making, architecture & design patterns, limits & quotas, security, configuration, integrations & coding patterns, and deployment. It combines local quick-reference content with remote documentation fetching capabilities.

## How to Use This Skill

> **IMPORTANT for Agent**: Use the **Category Index** below to locate relevant sections. For categories with line ranges (e.g., `L35-L120`), use `read_file` with the specified lines. For categories with file links (e.g., `[security.md](security.md)`), use `read_file` on the linked reference file

> **IMPORTANT for Agent**: If `metadata.generated_at` is more than 3 months old, suggest the user pull the latest version from the repository. If `mcp_microsoftdocs` tools are not available, suggest the user install it: [Installation Guide](https://github.com/MicrosoftDocs/mcp/blob/main/README.md)

This skill requires **network access** to fetch documentation content:
- **Preferred**: Use `mcp_microsoftdocs:microsoft_docs_fetch` with query string `from=learn-agent-skill`. Returns Markdown.
- **Fallback**: Use `fetch_webpage` with query string `from=learn-agent-skill&accept=text/markdown`. Returns Markdown.

## Category Index

| Category | Lines | Description |
|----------|-------|-------------|
| Troubleshooting | L37-L42 | Troubleshooting ExpressRoute resiliency and asymmetric routing issues, plus FAQs on connectivity models, supported services, bandwidth, and pricing to resolve design or outage-related questions. |
| Best Practices | L43-L50 | Best practices for ExpressRoute: upgrading circuit bandwidth, using BGP communities in complex topologies, QoS for Skype voice, and migrating to new gateway hardware. |
| Decision Making | L51-L59 | Guidance on choosing ExpressRoute connectivity models, VNets and gateways, planning gateway SKU changes, and estimating/optimizing ExpressRoute costs. |
| Architecture & Design Patterns | L60-L70 | Designing resilient, highly available ExpressRoute topologies, multi-circuit routing, coexistence with S2S VPN, DR/backup patterns, and using Microsoft peering for PSTN services. |
| Limits & Quotas | L71-L79 | ExpressRoute limits on FastPath, gateways, routes, and provider circuits, including rate limiting, quotas, monitoring advertised routes, and FAQs on connectivity scale and constraints. |
| Security | L80-L89 | Encryption (IPsec, MACsec), NAT rules, RBAC roles, and security best practices for protecting ExpressRoute circuits and traffic |
| Configuration | L90-L126 | Configuring and managing ExpressRoute circuits, gateways, routing/peering (IPv4/IPv6, BGP, NAT, filters), Global Reach, monitoring, resiliency, and linking VNets via portal, PowerShell, or CLI |
| Integrations & Coding Patterns | L127-L133 | Automating ExpressRoute circuit creation/management with PowerShell or Azure CLI, and configuring a site-to-site VPN that runs over ExpressRoute Microsoft peering. |
| Deployment | L134-L140 | Guides for deploying and migrating ExpressRoute circuits/gateways, understanding Direct SKUs, testing multi-site resiliency, and automating setup with ARM templates, PowerShell, and Terraform. |

### Troubleshooting
| Topic | URL |
|-------|-----|
| Test and validate resiliency of redundant ExpressRoute circuits | https://learn.microsoft.com/en-us/azure/expressroute/evaluate-circuit-resiliency |
| Diagnose and resolve asymmetric routing with ExpressRoute | https://learn.microsoft.com/en-us/azure/expressroute/expressroute-asymmetric-routing |

### Best Practices
| Topic | URL |
|-------|-----|
| Apply best practices for upgrading ExpressRoute circuit bandwidth | https://learn.microsoft.com/en-us/azure/expressroute/about-upgrade-circuit-bandwidth |
| Manage complex ExpressRoute networks using BGP communities | https://learn.microsoft.com/en-us/azure/expressroute/bgp-communities |
| Apply QoS requirements for Skype voice over ExpressRoute | https://learn.microsoft.com/en-us/azure/expressroute/expressroute-qos |
| Migrate legacy ExpressRoute gateway connections to new hardware | https://learn.microsoft.com/en-us/azure/expressroute/howto-recreate-connections |

### Decision Making
| Topic | URL |
|-------|-----|
| Select and configure ExpressRoute virtual network gateways | https://learn.microsoft.com/en-us/azure/expressroute/expressroute-about-virtual-network-gateways |
| Choose the right Azure ExpressRoute connectivity model | https://learn.microsoft.com/en-us/azure/expressroute/expressroute-connectivity-models |
| Plan and execute ExpressRoute gateway SKU migration | https://learn.microsoft.com/en-us/azure/expressroute/gateway-migration |
| Plan and manage Azure ExpressRoute costs | https://learn.microsoft.com/en-us/azure/expressroute/plan-manage-cost |
| Choose VNet connectivity options over ExpressRoute | https://learn.microsoft.com/en-us/azure/expressroute/virtual-network-connectivity-guidance |

### Architecture & Design Patterns
| Topic | URL |
|-------|-----|
| Design resilient Azure ExpressRoute network architectures | https://learn.microsoft.com/en-us/azure/expressroute/design-architecture-for-resiliency |
| Design disaster recovery with ExpressRoute private peering | https://learn.microsoft.com/en-us/azure/expressroute/designing-for-disaster-recovery-with-expressroute-privatepeering |
| Architect high availability for Azure ExpressRoute | https://learn.microsoft.com/en-us/azure/expressroute/designing-for-high-availability-with-expressroute |
| Optimize routing across multiple ExpressRoute circuits | https://learn.microsoft.com/en-us/azure/expressroute/expressroute-optimize-routing |
| Architect coexisting ExpressRoute and S2S VPN connections | https://learn.microsoft.com/en-us/azure/expressroute/how-to-configure-coexisting-gateway-portal |
| Design S2S VPN backup for ExpressRoute private peering | https://learn.microsoft.com/en-us/azure/expressroute/use-s2s-vpn-as-backup-for-expressrou