Technical data

Troubleshooting Techniques and Tools

1.2 Isolating Problems

You can also obtain information using the following commands:

TCPIP> SHOW INTERFACE

Packets

Interface IP_Addr Network mask Receive Send MTU

LO0 127.0.0.1 255.0.0.0 137 137 4096

WE0 10.10.2.1 255.255.255.0 5089 4191 1500

TCPIP> SHOW CONFIGURATION INTERFACE

Interface: LO0

IP_Addr: 127.0.0.1 NETWRK: 255.0.0.0 BRDCST:

Interface: WE0

IP_Addr: 10.10.2.1 NETWRK: 255.255.255.0 BRDCST: 10.10.2.255

If you are not familiar with IP addressing and the concepts of subnet and

broadcast masks, review the information in HP TCP/IP Services for OpenVMS

Management before proceeding with troubleshooting tasks.

1.2.3 Displaying and Modifying the Internet-to-Ethernet Translation Tables

Use the

arp

utility or the SHOW ARP management command to check the

IP address to Ethernet address translation entries in the Address Resolution

Protocol (ARP) table. This is useful if you think incorrect entries are being added

to the ARP table. For example, if you enter a command and an unexpected host

responds, you may have two systems deﬁned with the same IP address in the

ARP table.

To display entries in the ARP table, enter the following command:

$ TCPIP SHOW ARP

Cnt Flags Timer Host Phys Addr

1: UCS 451 160.20.0.10 08-00-2b-39-c7-ac

2: UC 0 160.20.0.100 aa-00-04-00-8d-13

3: UC 3 160.20.0.173 00-00-f8-45-a0-b4

4: UC 14 160.20.32.94 00-00-f8-00-f7-41

5: UC 50 160.20.64.69 00-d0-b7-19-78-a4

6: UCS 9 160.20.64.132 00-50-8b-72-7f-ff

7: UCS 150 160.20.80.124 00-50-8b-4d-91-b3

The following TCP/IP Services management commands allow you to conﬁgure the

hardware addresses for remote IP addresses:

• SET ARP allows you to add the hardware address to the ARP table.

• SET PROTOCOL ARP allows you specify the time interval for ARP to hold

information in its cache. Use the SET CONFIGURATION PROTOCOL ARP

command to set this information in the permanent conﬁguration database.

For more information about these commands, refer to the HP TCP/IP Services

for OpenVMS Management Command Reference manual.

For information about using the

arp

utility, refer to Appendix A.

1–6 Troubleshooting Techniques and Tools