Netgear XCM8806 Chassis User Manual - Page 605
Extended IPv4 Host Cache, Introduction to Hardware Forwarding Tables,
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NETGEAR 8800 User Manual • Extended IPv4 Host Cache on page 605 • ECMP Hardware Table on page 609 Extended IPv4 Host Cache The extended IPv4 host cache feature provides additional, configurable storage space on select switches to store additional IPv4 hosts in the hardware routing tables. This feature is supported on NETGEAR 8800 switches. Some switches do not support this feature because they have more than enough storage space for IPv4 hosts, and some do not have the hardware required to support this feature. All switches support slow-path routing (using software routing tables), so adding more entries in the hardware routing table is a performance feature, which allows more hosts to benefit from fast-path routing. If your switch log was displaying table-full messages in XCM8800, you might be able to improve switch performance and avoid the table-full messages by configuring the extended IPv4 host cache feature. To use the extended IPv4 host cache feature effectively, it helps to understand how the hardware tables operate on the switches that support this feature. The hardware forwarding tables controlled by this feature store entries for the following: • IPv4 local and remote hosts • IPv4 routes • IPv6 local hosts • IPv6 routes • IPv4 multicast The extended IPv4 host cache feature works by customizing the forwarding table space allotted to these components. The following sections provide more information about the Extended IPv4 Host Cache feature: • Introduction to Hardware Forwarding Tables on page 605 • LPM Table Management on page 606 • Extended IPv4 Host Cache Management Guidelines on page 607 • IPv4 Host Entry Population Sequence on page 608 • Calculating the Number of Routes Needed on page 609 • Lower-Capacity Hardware on page 609 Introduction to Hardware Forwarding Tables The extended IPv4 host cache feature relates to the four hardware forwarding tables shown in Figure 63. Chapter 20. IPv4 Unicast Routing | 605
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