HP-UX LAN Administrator's Guide (Feburary 2007)
Table Of Contents
- About This Document
- 1 New for the HP-UX 11i v3 Release
- 2 Installing HP-UX LAN
- 3 Configuring HP-UX LAN Using SAM
- 4 Manually Installing and Configuring HP-UX LAN
- 5 Troubleshooting HP-UX LAN
- Troubleshooting Overview
- Troubleshooting Q & A
- LAN Interface Card Statistics
- 100Base-T Checklist
- Diagnostic Flowcharts
- Flowchart 1: Configuration Test
- Flowchart 2: Configuration Test continued
- Flowchart 3: Configuration Test continued
- Flowchart 4: Network Level Loopback Test
- Flowchart 5: Network Level Loopback Test continued
- Flowchart 6: Transport Level Loopback Test (using Internet Services)
- Flowchart 7: Link Level Loopback Test
- Flowchart 8: LAN Connections Test
- Flowchart 9: Gateway Remote Loopback Test
- Flowchart 10: Gateway Remote Loopback Test continued
- Flowchart 11: Subnet Test
- 6 LAN Resources
- 7 Network Addressing
- Overview of Network Addressing Schemes
- Networking Terminology
- Network Addresses and Node Names
- Internet Addresses
- Subnet Addresses
- Configuring Gateways on Fixed-Length Subnets
- Variable-Length Subnet Addressing
- Configuring Gateways on Variable-Length Subnets
- Configuring Gateways on Supernets
- IP Multicast Addresses
- Virtual IP (VIP) Addresses
- CIDR - Classless Inter-Domain Routing
- 8 LAN Device and Interface Terminology
Network AddressingDRAFT COPY
Networking Terminology
Chapter 794
interface, you can configure the subsequent interfaces in any order. Note that the IP
addresses assigned to a card may be on the same subnet or on different subnets. See the
section “Interfaces,” in Chapter 7 for more information about logical interfaces and interface
names.
An initial interface cannot be removed from the system until all subsequent logical interfaces
are removed. You can remove subsequent interfaces from the system with the ifconfig
command, as in the following example:
ifconfig lan1:1 inet 0.0.0.0
The initial interface (for example, lan1) can then be removed from the system with the
ifconfig command, as in the following example:
ifconfig lan1 unplumb
A loopback interface does not have a hardware device associated with it. The name of this
type of interface is lo0, denoting the loopback interface. A loopback interface is automatically
created by the TCP/IP stack even if the system is not connected to a network.
Gateway
A gateway is a device used to connect two or more networks. The gateway serves to route
information among the networks. An HP-UX Server with two or more LAN cards installed
may act as a LAN-to-LAN gateway. Such a node may also be referred to as a LAN-to-LAN
router or IP router. If a node is a gateway, it affects how you configure and maintain LAN
software. Refer to node D in the network maps in Figure 7-7 and Figure 7-13 for examples of
gateways. A gateway system has to have at least two network interfaces configured, one for
each network to which it belongs. A gateway can be either a router or a system.
Routing Table
Each node on the LAN has a routing table. A routing table contains information about the
route to nodes on other LANs. The connections to other LANs are made through gateways.
ARP Cache
Each interface card on a system is identified by an IP address and a station address. The ARP
cache contains the IP address of a remote interface and the station address which is used to
send packets to that IP address. If the remote system is not on the same physical network, the
station address in the ARP cache is for an interface on a gateway.
Usually, an ARP cache entry is automatically created when the system needs to send the first
packet to a remote IP address. ARP cache entries are usually deleted automatically when they
have not been used for a period of time.