Diagnostic Flowcharts

Execute: telnet <hostname> to remote host. Try to connect using telnet to a remote host.

Succeeds? If telnet succeeds, stop. The system connects using TCP over IPv6 through the Transport Layer (OSI Layer 4).

Connection Refused? Trying to connect to a remote system where HP-UX 11i v2 IPv6 is not installed can cause this message.

Network Reachable? If it is, go to F, otherwise continue to E.

Check for Network Connectivity. Ensure network connectivity by following the steps in Flowchart 2.

Ensure IPv6 installed on remote node. If telnet still fails, examine the etc/inetd.conf file on the remote system.

Execute ping to remote IPv6 “host name”. Using ping, send an ICMPv6 message to the remote host with which you are having problems connecting. For example, the remote host name is hpindon. Enter:

ping -f inet6 hpindon

ping successful? A message is printed on stdout for each ping packet returned by the remote host. If packets are being returned, your system has network level connectivity to the remote host.

Execute ping to remote IPv6 address. Using ping, send a message to the IPv6 address of the remote host. For example,

ping -f inet6 8:7:6:5:4:3:2:1

Network unreachable? If so, examine the status of the local LAN interface first. If not, proceed to F.

Local LAN interface up? Execute ifconfig on the local interface to be sure it is configured up. If it is not, go to G. If it is up, call your HP representative for help.

Command hangs? If a message is not returned after executing ping, go to Flowchart 4, otherwise go to H.

Configure interface up. If you find the local interface is not up, execute ifconfig with the appropriate flags set. Begin Flowchart 2 again. If the problem persists, go to Flowchart 4.

Unknown host? (Error= Unknown host <hostname>?) If so, there is a problem with the IPv6 address configuration for the host <hostname> in the /etc/hosts file or on the name server. Go to Flowchart 3. Otherwise, proceed to I.

No route to host? (Error= Sendto: No route to host?) Use netstat -rn to examine the routing table. If there is no route to host, go to J. Otherwise, call your HP representative for help.

Check IPv6 Router or add route table entry. Add a route table entry to that host, or ensure that the IPv6 router advertises correct prefixes. Then try Flowchart 2 again. If the problem persists, go to Flowchart 6.

Check /etc/hosts and /etc/nsswitch.conf files. If needed, add a missing host name or IPv6 address. If the IPv6 address for the host is in /etc/hosts, ensure that you have an /etc/nsswitch.conf file entry with an appropriate ipnodes policy. For example,
ipnodes: DNS [NOTFOUND=continue] files

and start again with Flowchart 3.

Using DNS? If your name and IPv6 address resolution policy use DNS as the primary resolver, go to C. Otherwise, proceed to E.

Can you add a Host Name to the DNS Server? Are you a DNS administrator? If so, continue on to D, otherwise proceed to F.

Add Entry to DNS Server. Refer to the BIND 9.2.0 information in the HP-UX IP Address and Client Management Administrator’s Guide for details (available at http://docs.hp.com). Then retry Flowchart 2.

Add entry to /etc/hosts. If your name and IPv6 address resolution policy uses /etc/hosts as the primary resolver, add a correct IPv6 address and host name to the local /etc/hosts file. Then retry Flowchart 2.

Add entry to /etc/hosts and ensure that nsswitch.conf is configured properly. Add a correct IPv6 address and host name to the local /etc/hosts file. Ensure that your IPv6 address resolution policy, specified with the ipnodes keyword in /etc/nsswitch.conf includes using “files” ( /etc/hosts) in the policy. Then retry Flowchart 2.

ping -f inet6 hostname. Test connectivity to the remote host using the ping command.

ping successful? If ping -f inet6 <hostname> succeeds using a host name and IPv6 address from /etc/hosts, DNS needs updating, proceed to I. If ping fails, examine the /etc/hosts, /etc/resolv.conf, and /etc/nsswitch.conf files on both the local and remote hosts. If all look correct, call your HP representative for help.

Work with DNS Administrator to add entry to DNS Server. When entry is added, retry Flowchart 2 to ensure that DNS correctly resolves host names and IPv6 addresses.

Execute: ifconfig <interface>inet6. Execute ifconfig on the interface you want to test. For example, to view LAN interface lan0, enter:

ifconfig lan0 inet6

ifconfig successful? ifconfig succeeds when the output shows an Internet address and the flags: UP, RUNNING, MULTICAST, ONLINK. If successful, go to E, if not continue to C.

Any error message returned? If ifconfig fails and displays an error message, go to Flowchart 5. Flowchart 5 shows what to do based on the error message. Otherwise continue to D.

Correct ifconfig with non-default flag settings. If ifconfig returns an unexpected flag setting, re-execute the command with the proper setting. For more information, refer to the ifconfig(1M) man page. Start again with Flowchart 4.

Execute: netstat -inf -inet6. If ifconfig succeeds, then the network interface is configured correctly. netstat -i displays the number of incoming (Ipkts) and outgoing (Opkts) packets passed through an interface. No increase in the number of incoming or outgoing packets would indicate LAN card I/0 problems.

Suspect LAN card I/O problems? If the statistics indicate possible LAN card problems, go to G, otherwise go to Flowchart 2 to test Network Connectivity.

Execute: lanadmin. Use lanadmin to ensure the LAN card is operational. A substantial increase in the number of the Ierrs and Oerrs during a file transfer attempt might indicate transmission problems.

Problem resolved? If you found and corrected the LAN card problem, return to step E to verify the correction. If corrected, re-execute ifconfig to bring up the interface, then go to Flowchart 2. If the problem persists, call your HP representative for help.

Is error message “No such interface name”? If not, go to F. If so, the interface name passed to ifconfig does not exist on the system. Using lanscan, verify the spelling and names of the interfaces on the system.

If the system contains more than one LAN card, make sure the correct number of LAN cards was configured into the kernel and that an ifconfig command was executed for each interface.

Execute: lanscan. E xecute lanscan to display information about the LAN cards in your system.

Was correct interface name used? Configure interface using ifconfig with the correct interface name. After reconfiguring using the correct interface name, start again with Flowchart 4.

Is Hardware State UP? Verify the state of the hardware with the output from the lanscan command. If the Hardware State is UP call your HP representative for help, otherwise continue to E.

Execute: lanadmin. e lanadmin command to reset the LAN card. Go to Flowchart 4.

Any other error message. Interpret any other error message and take the appropriate action. Then repeat flowchart 4. If you receive the same error message again, call your HP representative for help.

Execute: ping from known good host through gateway to known good host on remote network. T his tests router connectivity to the remote network. For more information on ping, refer to the ping(1M) man page.

ping successful? If ping -f inet6 succeeded, return to Flowchart 2. If ping -f inet6 failed, the problem may exist in the routing table for the problem host. Continue to C.

Execute: netstat -rnf inet6. To display gateway routing information in numerical form, execute: netstat -rnf inet6

Direct route to remote or default route to gateway? If the route exists, go to F. If not, continue to E to add a new route.

Add route entry on local system. Use the route command to add a route entry to the route table on the local system. Refer to route(1M) for a complete description of the command. Or if an IPv6 router on the LAN advertises default routes, wait a few minutes to see if a route advertisement is added to the default router list. Start again with Flowchart 6.

Correct router configured? If your local host has a route to the correct router, then retry Flowchart 6 from the remote node. If the remote node’s routing is configured properly, and both the local and remote nodes can connect to their respective routers, then contact your ISP or network administrator to verify network-to-network connectivity.

Change route entry on local system or router. If the routing information is incorrect, correct it using route, or verify that the IPv6 router is advertising proper subnet prefixes. Then retry Flowchart 2 to test network connectivity.