3/9/2024 0 Comments Netscreen ssg5 loopback pingWhen the device is forwarding packets, all route lookups are done based on the destination IP address. Traditionally, all routing devices configure routes for the destination IP address and provide the next-hop gateway address. You configure the path for the destination IP address of the packet. It is common to configure destination IP static routes. You can configure any of the following static routes on the firewall: This chapter concentrates on the static route configuration and route preferences. In ScreenOS software, VRs are populated with routes from connected/host routes (derived from interface IP addresses), static routes, dynamic routing protocols (such as OSPF, BGP, RIP, the Internet Group Management Protocol, and the Protocol Independent Multicast protocol), and imported routes from other VRs.Įach VR has several routing tables: the destination IP-based table, the source IP-based table, the source interface-based table, the policy-based route table, and the multicast route table. Refer to Chapter 1 for information on how to configure and separate the routing instances on the firewall. You can configure interfaces to be in different zones. The system-defined VRs on the device are trust-vr and untrust-vr. Each interface is bound to a zone, and each zone is bound to a VR (see Figure 4-1). Each VR has its own routing tables, which provide routing security by separating the routing tables on the firewall. The ScreenOS software has the concept of VRs, which are routing table instances. You can change the interface mode to route mode using the command set interface e1 route. In route mode, NAT is not performed on any traffic, and the traffic is forwarded with the original IP address that the firewall received in the packet. If the interface belongs to a user-defined zone such as Private, the device does not perform NAT on the traffic, and you would have to cross the VRs for NAT to happen. The firewall performs NAT on traffic only if the interface belongs to a predefined Trust zone and the egress interface goes to the Untrust zone. This means you want NAT to be performed on ingress traffic on this interface while crossing the firewall. To configure the ingress interface to be in NAT mode, use the command set interface e1 nat. If you assign interfaces to Trust, Untrust, or any user-defined Layer 3 zones and assign IP addresses to the interfaces, the device operates in NAT or route mode. If you assign interfaces to V1-Trust, V1-Untrust, or any user-defined Layer 2 zone, the device operates in transparent mode, which means that the firewall operates as a switch on the network. By default, when you put an interface in the Trust zone, it operates in NAT mode for all other zones, the interface operates in route mode. The system mode is determined based on how you configure the interfaces. This example shows a system operating in NAT/route mode: SSG-> get sys You can check in which mode the system is operating with the get system command. When the device is in transparent mode, the device utilizes the Media Access Control (MAC) table to forward packets while in NAT/route mode, the device uses the route table to make forwarding decisions. The routing table is used differently in each mode. In ScreenOS software, you can deploy a firewall in three different system modes: Network Address Translation ( NAT) mode, route mode, and transparent mode. The collection of all paths is kept in a database called the routing table. Used to identify the route for filtering or redistribution into other instances. This is where the packet should be forwarded for the IP address. The gateway IP address, and the interface or Virtual Router (VR). This is the IP address for which the route is defined.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |