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
DRAFT COPY Troubleshooting HP-UX LAN
Troubleshooting Q & A
Chapter 5 43
Answer: On IEEE802.3/Ethernet networks, a collision occurs when two or more stations try to
transmit data simultaneously. A deferred transmission occurs if the network is busy when a
station attempts to transmit data. The number of collisions and deferred transmissions on a
node is directly related to the network load. As the network load increases, the number of
collisions and deferred transmissions also increase.
When high-performance systems are placed on a LAN with lower-performance systems (HP or
non-HP systems), it is possible for the high-performance systems to use a higher percentage of
the LAN bandwidth with network traffic intensive applications. High-performance systems
generate network traffic at a 10Mbits/s link rate, and lower-performance systems cannot
match this rate. Heavily loaded LAN networks can result in lower throughput performance on
lower-performance systems.
In general, the short term average load on an IEEE802.3/Ethernet LAN should not exceed
more than 70% of the total bandwidth of the LAN. When it does exceed 70% of the total
bandwidth, network performance begins to degrade due to an increase in collisions and
deferred transmissions. When it consistently exceeds 70% of the total bandwidth, you may
need to reconfigure the systems on your LAN. If you notice throughput/performance
degradation on your system, contact your local HP Representative for additional assistance
and consultation.
“No such interface”: After I booted my server, I found that networking failed. I found the
following error in the /var/adm/rc.log file:
ifconfig lan0: no such interface
How do I resolve this problem?
Answer: This problem is caused by the LAN driver software disabling the LAN card because it
was not connected to the LAN, or the LAN was down. Use lanadmin or the reset operation of
the nwmgr command to reset the LAN card and run ifconfig to bring the card up. See
lanadmin(1M) or nwmgr(1M) for details.
“No such interface”: When I configure an interface, ifconfig returns the error “no such
interface.” What should I do?
Answer: The numeric portion of the interface name is incorrect. Run the lanscan or nwmgr
command to obtain a list of interface names.
“Plumbing error”: When I configure an interface, ifconfig returns a “Plumbing error”
message. What should I look for?
Answer: The interface name specified in the ifconfig run string is not defined in the /dev
directory or is not a streams driver. The network device files /dev/ip and /dev/tcp are not
defined.