Logical Router Overview
Table of Contents
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- Tap Interfaces
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- Layer 2 and Layer 3 Packets over a Virtual Wire
- Port Speeds of Virtual Wire Interfaces
- LLDP over a Virtual Wire
- Aggregated Interfaces for a Virtual Wire
- Virtual Wire Support of High Availability
- Zone Protection for a Virtual Wire Interface
- VLAN-Tagged Traffic
- Virtual Wire Subinterfaces
- Configure Virtual Wires
- Configure an Aggregate Interface Group
- Configure Bonjour Reflector for Network Segmentation
- Use Interface Management Profiles to Restrict Access
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- DNS Overview
- DNS Proxy Object
- DNS Server Profile
- Multi-Tenant DNS Deployments
- Configure a DNS Proxy Object
- Configure a DNS Server Profile
- Use Case 1: Firewall Requires DNS Resolution
- Use Case 2: ISP Tenant Uses DNS Proxy to Handle DNS Resolution for Security Policies, Reporting, and Services within its Virtual System
- Use Case 3: Firewall Acts as DNS Proxy Between Client and Server
- DNS Proxy Rule and FQDN Matching
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- NAT Rule Capacities
- Dynamic IP and Port NAT Oversubscription
- Dataplane NAT Memory Statistics
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- Translate Internal Client IP Addresses to Your Public IP Address (Source DIPP NAT)
- Enable Clients on the Internal Network to Access your Public Servers (Destination U-Turn NAT)
- Enable Bi-Directional Address Translation for Your Public-Facing Servers (Static Source NAT)
- Configure Destination NAT with DNS Rewrite
- Configure Destination NAT Using Dynamic IP Addresses
- Modify the Oversubscription Rate for DIPP NAT
- Reserve Dynamic IP NAT Addresses
- Disable NAT for a Specific Host or Interface
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- Network Packet Broker Overview
- How Network Packet Broker Works
- Prepare to Deploy Network Packet Broker
- Configure Transparent Bridge Security Chains
- Configure Routed Layer 3 Security Chains
- Network Packet Broker HA Support
- User Interface Changes for Network Packet Broker
- Limitations of Network Packet Broker
- Troubleshoot Network Packet Broker
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- Enable Advanced Routing
- Logical Router Overview
- Configure a Logical Router
- Create a Static Route
- Configure BGP on an Advanced Routing Engine
- Create BGP Routing Profiles
- Create Filters for the Advanced Routing Engine
- Configure OSPFv2 on an Advanced Routing Engine
- Create OSPF Routing Profiles
- Configure OSPFv3 on an Advanced Routing Engine
- Create OSPFv3 Routing Profiles
- Configure RIPv2 on an Advanced Routing Engine
- Create RIPv2 Routing Profiles
- Create BFD Profiles
- Configure IPv4 Multicast
- Create Multicast Routing Profiles
- Create an IPv4 MRoute
Logical Router Overview
On a firewall with Advanced Routing enabled, a logical
router participates in Layer 3 routing.
The firewall uses logical routers to
obtain Layer 3 routes to other subnets by you manually defining
static routes or through participation in one or more Layer 3 routing
protocols (dynamic routes). The routes that the firewall obtains
through these methods populate the IP routing information base (RIB)
on the firewall. When a packet is destined for a different subnet
than the one it arrived on, the logical router obtains the best
route from the RIB, places it in the forwarding information base
(FIB), and forwards the packet to the next hop router defined in
the FIB. The firewall uses Ethernet switching to reach other devices
on the same IP subnet. (An exception to one best route going in the
FIB occurs if you are using ECMP, in which
case all equal-cost routes go in the FIB.)
The Ethernet, VLAN, and tunnel interfaces defined on the firewall
receive and forward Layer 3 packets. The destination zone
is derived from the outgoing interface based on the forwarding criteria,
and the firewall consults policy rules to identify the security
policies that it applies to each packet. In addition to routing
to other network devices, logical routers can route to other logical
routers within the same firewall if a next hop is specified to point
to another logical router.
You can Configure Layer 3 Interfaces to participate
with dynamic routing protocols (BGP, OSPF, OSPFv3, or RIP) as well
as add static routes. You can also create multiple logical routers,
each maintaining a separate set of routes that aren’t shared between
logical routers, enabling you to configure different routing behaviors
for different interfaces.
You can configure dynamic routing from one logical router to another by configuring a loopback
interface in each logical router, creating a static route between the two loopback
interfaces, and then configuring a dynamic routing protocol to peer between these two
interfaces. The firewall supports only one hop between logical routers. For example,
with logical routers A, B, and C, a route cannot go from A to B to C; it would have to
go from A to C.
Each Layer 3 Ethernet, loopback, VLAN, and tunnel interface defined
on the firewall must be associated with a logical router. While
each interface can belong to only one logical router, you can configure
multiple routing protocols and static routes for a logical router.
Regardless of the static routes and dynamic routing protocols you
configure for a logical router, one general configuration is required.