Chapter 13 Policy and Static Routes

•Use the Static Route screens (see Section 13.3 on page 291) to list and configure static routes.

13.1.2What You Need to Know

Policy Routing

Traditionally, routing is based on the destination address only and the ZyWALL takes the shortest path to forward a packet. IP Policy Routing (IPPR) provides a mechanism to override the default routing behavior and alter the packet forwarding based on the policy defined by the network administrator. Policy-based routing is applied to incoming packets on a per interface basis, prior to the normal routing.

How You Can Use Policy Routing

•Source-Based Routing – Network administrators can use policy-based routing to direct traffic from different users through different connections.

•Bandwidth Shaping – You can allocate bandwidth to traffic that matches routing policies and prioritize traffic (however the application patrol’s bandwidth management is more flexible and recommended for TCP and UDP traffic). You can also use policy routes to manage other types of traffic (like ICMP traffic) and send traffic through VPN tunnels.

Note: Bandwidth management in policy routes has priority over application patrol bandwidth management.

•Cost Savings – IPPR allows organizations to distribute interactive traffic on high- bandwidth, high-cost paths while using low-cost paths for batch traffic.

•Load Sharing – Network administrators can use IPPR to distribute traffic among multiple paths.

•NAT - The ZyWALL performs NAT by default for traffic going to or from the WAN interfaces. A routing policy’s SNAT allows network administrators to have traffic received on a specified interface use a specified IP address as the source IP address.

Note: The ZyWALL automatically uses SNAT for traffic it routes from internal interfaces to external interfaces. For example LAN to WAN traffic.

Static Routes

The ZyWALL usually uses the default gateway to route outbound traffic from computers on the LAN to the Internet. To have the ZyWALL send data to devices not reachable through the default gateway, use static routes. Configure static routes if you need to use RIP or OSPF to propagate the routing information to other routers. See Chapter 14 on page 297 for more on RIP and OSPF.

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ZyWALL USG 50 User’s Guide