HP-UX Networking Administration

An IPv4 address is 32 bits long, typically represented as four octets (e.g., 192.168.1.1). Each octet contains 8 bits, totaling 32 bits. IPv6 addresses are 128 bits long, while MAC addresses are 48 bits.

The Address Resolution Protocol (arp) command displays and modifies the translation tables used to map Internet IP addresses to physical Ethernet MAC addresses.

The lanscan command (HP-UX) displays the status of network interface cards, showing whether each NIC is up or down. nslookup queries DNS, ping tests connectivity, and arp shows MAC-to-IP mappings.

The nsquery command on HP-UX is used to query the name service switch configuration to resolve hostnames and verify that DNS/BIND resolution is working properly.

On HP-UX, the startup script /sbin/init.d/nfs.core is responsible for starting core NFS services, including the rpcbind daemon during system boot.

The netstat command with the -r option is used to display the kernel routing tables on UNIX and Linux systems, showing how network packets are routed.

Neighbor Discovery Protocol (NDP) is a core component of IPv6 that replaces ARP in IPv4 networks. It handles address resolution, neighbor unreachability detection, and duplicate address detection. DHCP is for configuration, ARP is IPv4-specific, and OSPF is a routing protocol.

In HP-UX, the userdbset command enables system-level auditing for individual users when not in Trusted Mode. This allows per-user audit configuration. audsys and audusr are not standard commands, and usermod is for user account modification.

HP-UX Secure Shell defaults to the SSH-2 protocol, which is much more secure and robust than the older, deprecated SSH-1 protocol.

The linkloop command tests MAC address connectivity between network cards by sending packets with the source MAC set to the destination MAC, testing if the card can receive its own transmissions. It doesn't test router activity, MTU size, or IP-level loopback (ping does that).

The /etc/bootptab file contains the configuration information sent in response to BOOTP requests, including IP addresses, hostnames, and other boot parameters for each client. /etc/services lists port numbers, /etc/inetd.conf configures the inet daemon, and /etc/bootp.conf is not the standard configuration file location.

IP multiplexing (or IP aliasing) on a UNIX host refers to assigning and binding multiple IP addresses to a single physical network interface card.

HP-UX 11i v3 introduced the nwmgr (Network Manager) command as a unified interface for network configuration, replacing several legacy utilities. inkloop, lanscan, and lanadmin were deprecated in favor of nwmgr. netstat and ifconfig remain active commands - netstat displays network statistics and ifconfig (or hp ifconfig on newer HP-UX) configures network interfaces.

HP-UX 11i v3 controls NFS version support through kernel configuration parameters NFS_SERVER_VERSMIN and NFS_SERVER_VERSMAX. By setting both to 4, only NFSv4 is enabled. HP-UX v3 does support NFSv4. Recompiling the kernel is not required - these are tunable parameters. NFSv2/v3 can be disabled; they are not mandatory.

The /etc/rmtab file on an NFS server maintains a list of remote clients that currently have the server's exported file systems mounted.

An IPv4 address is a 32-bit numeric address written as four decimal numbers separated by periods. IPv6 addresses, by contrast, are 128 bits long.

IPFilter on HP-UX 11i v3 creates extensive logs for auditing, supports legacy X.25 interfaces (important for enterprise networks), and provides Network Address Translation (NAT) capabilities. It is not installed/enabled by default (requires setup), and the configuration is primarily text-based through ipf rules files, not a GUI tool.

The arp command is used to display and manipulate the Address Resolution Protocol (ARP) cache, which maps IP addresses (Internet) to physical MAC addresses (Ethernet).

NFS version 4 introduces strong integrated security (via Kerberos), integrated file locking (eliminating NLM), and operates over a single TCP port (2049), which greatly simplifies firewall configuration.