HP Auto Port Aggregation Administrator's Guide HP-UX 11i v3 (766140-001, March 2014)

1. Ensure that the network devices are configured properly on the
local host, using the netstat -i command.
2. Verify that the routing tables on the local host are correct, using the
netstat -r command.
If a host is not known, the following message is displayed:
unknown host
Complete the following steps:
1. Verify that the user is trying to reach the remote host using a valid
host name.
2. Verify that the remote host is in another name domain and that the
user specified the full domain name.
3. If your site uses the Domain Name System (DNS) for name-to-address
translation, look in the /etc/nsswitch.conf file to see if nis
is specified as a service for the hosts database entry. If it is not,
add it. Also, verify that the DNS service has information about the
remote host.
4. If your site uses the NIS name service for name-to-address
translation, look in the /etc/nsswitch.conf file to see if nis
is specified as a service for the hosts database entry. If it is not,
add it. Also, verify if the NIS service has information about the
remote host.
5. If your /etc/nsswitch.conf file lists files as the only
name-to-address translation mechanism, the /etc/hosts file does
not have information on the remote host. See nsswitch.conf(4) for
more information.
If a remote host is not reachable, the following message is displayed:
host is unreachable
Complete the following steps:
1. Inspect the cabling between the local host and the link partner.
2. Perform a loopback test on your own system by using the ping
command. If this is successful, your system is operating properly to
the Network Layer (OSI Layer 3).
3. Verify the remote host is running, using the ping command. If the
remote host does not respond, ask the host's system administrator
to start the host. For additional information about the ping
command, see “Testing access to Internet network hosts” (page 68).
4. Verify that an entry exists for the remote host in your system's ARP
cache by entering the following command:
# arp hostname
If the entry is wrong or incomplete, enter the correct station address
by using the arp command. See arp(1M) for more information.
5. Make sure the network devices are configured properly on the local
host, using the netstat -i command.
6. Verify that the routing tables on the local host are correct, using the
netstat -r command. Use the ping command to determine
whether the IP router is reachable.
66 Troubleshooting HP APA