Cisco 7604 Configuration Guide - Page 714

Glossary MTU multicast Maximum transmission unit, the maximum number of bytes in a packet that can flow efficiently across the network with best response time. For Ethernet, the default MTU is 1500 bytes, but each network can have different values, with serial connections having the smallest values. The MTU is described in RFC 1191. Multicast refers to a network addressing method in which the source transmits a packet to multiple destinations, a multicast group, simultaneously. See also PIM, SMR. N N2H2 A third-party, policy-oriented filtering application that works with the FWSM to control user web access. N2H2 can filter HTTP requests based on destination host name, destination IP address, and username and password. The N2H2 corporation was acquired by Secure Computing in October, 2003. NAT Network Address Translation. Mechanism for reducing the need for globally unique IP addresses. NAT allows an organization with addresses that are not globally unique to connect to the Internet by translating those addresses into a globally routable address space. NBAR Network-Based Application Recognition. NEM Network Extension Mode. Lets VPN hardware clients present a single, routable network to the remote private network over the VPN tunnel. NetBIOS Network Basic Input/Output System. A Microsoft protocol that supports Windows host name registration, session management, and data transfer. The FWSM supports NetBIOS by performing NAT of the packets for NBNS UDP port 137 and NBDS UDP port 138. netmask See mask. network In the context of FWSM configuration, a network is a group of computing devices that share part of an IP address space and not a single host. A network consists of multiple nodes or hosts. See also host, Internet, intranet, IP, LAN, and node. NMS network management system. System responsible for managing at least part of a network. An NMS is generally a reasonably powerful and well-equipped computer, such as an engineering workstation. NMSs communicate with agents to help keep track of network statistics and resources. node Devices such as routers and printers that would not normally be called hosts. See also host, network. nonvolatile storage, Storage or memory that, unlike RAM, retains its contents without power. Data in a nonvolatile storage memory device survives a power-off, power-on cycle or reboot. NP Network processor. NSAPI Network service access point identifier. One of two components of a GTP tunnel ID, the other component being the IMSI. See also IMSI. NSSA Not-so-stubby-area. An OSPF feature described by RFC 1587. NSSA was first introduced in Cisco IOS software release 11.2. It is a non-proprietary extension of the existing stub area feature that allows the injection of external routes in a limited fashion into the stub area. GL-12 Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM OL-20748-01