Netgear XCM8806 Chassis User Manual - Page 679

NETGEAR 8800 User Manual The translate option determines whether type 7 LSAs are translated into type 5 LSAs. When configuring an OSPF area as an NSSA, translate should only be used on NSSA border routers, where translation is to be enforced. If translate is not used on any NSSA border router in a NSSA, one of the ABRs for that NSSA is elected to perform translation (as indicated in the NSSA specification). The option should not be used on NSSA internal routers. Doing so inhibits correct operation of the election algorithm. Normal Area A normal area is an area that is not: • Area 0 • Stub area • NSSA Virtual links can be configured through normal areas. External routes can be distributed into normal areas. Virtual Links In the situation when a new area is introduced that does not have a direct physical attachment to the backbone, a virtual link is used. A virtual link provides a logical path between the ABR of the disconnected area and the ABR of the normal area that connects to the backbone. A virtual link must be established between two ABRs that have a common area, with one ABR connected to the backbone. Figure 72 illustrates a virtual link. Note: Virtual links cannot be configured through a stub or NSSA area. Virtual link ABR ABR Area 2 Area 1 Area 0 EX_044 Figure 72. Virtual Link Using Area1 as a Transit Area Chapter 24. OSPF | 679