Integrating Unix and NT Technology

TCP/IP UTILITIES

• If TCP/IP can’t communicate from a host to a remote host system, the TCP/IP utilities listed in the following sections won’t work correctly.
• If the systems are on different subnetworks and can’t communicate, remember that TCP/IP requires routing to communicate between subnetworks.
• If systems that were previously able to communicate can no longer communicate, suspect either your router(s) or changes in software configuration.
• Utilities that require user names and passwords on the remote host need a user account on the remote system. Trust relationships aren’t the same as achieving connectivity.


In the following sections, we cover six TCP/IP tools:


• Address Resolution Protocol (ARP)
• Hostname
• NETSTAT
• NSLOOKUP
• PING
• ROUTE
• Simple Network Management Protocol (SNMP)

ARP

• -a — Displays current ARP entries by interrogating the current protocol data. If inet_addr is specified, the IP and physical addresses for only the specified computer are displayed. If more than one network interface uses ARP, entries for each ARP table are displayed.
• -g — Same as -a.
• inet_addr — Specifies an Internet address.
• -N if_addr — Displays the ARP entries for the network interface specified by if_addr.
• -d — Deletes the host specified by inet_addr.
• -s — Adds the host and associates the Internet address inet_addr with the physical address eth_addr. The physical address is given as six hexadecimal bytes separated by hyphens. The entry is permanent.
• eth_addr — Specifies a physical address.
• if_addr — If present, this option specifies the Internet address of the interface whose address translation table should be modified. If it’s not present, the first applicable interface will be used.

Hostname

NETSTAT

• -a — Displays all connections and listening ports. (Server-side connections are normally not shown).
• -e — Displays Ethernet statistics. This option may be combined with the -s option.
• -n — Displays addresses and port numbers in numerical form.
• -s — Displays per-protocol statistics. By default, statistics are shown for TCP, UDP, and IP; the -p option may be used to specify a subset of the default.
• -p proto — Shows connections for the protocol specified by proto; proto may be TCP or UDP. If it’s used with the -s option to display per-protocol statistics, proto may be TCP, UDP, ICMP, or IP.
• -r — Displays the contents of the routing table.
• interval — Redisplays selected statistics, pausing the number of seconds specified by this option between each display. Press Ctrl+C to stop redisplaying statistics. If this parameter is omitted, NETSTAT will print the current configuration information once.

NSLOOKUP

• nslookup [-opt ...] — Interactive mode using default server
• nslookup [-opt ...] - server — Interactive mode using the server specified by server
• nslookup [-opt ...] host — Just look up host using default server
• nslookup [-opt ...] host server — Just look up host using server

PING

• -t — Pings the specified host until interrupted
• -a — Resolves addresses to host names
• -n count — Number of echo requests to send
• -l size — Sends buffer size
• -f — Sets “Don’t Fragment” flag in packet
• -i TTL — Time to live
• -v TOS — Type of service
• -r count — Records route for count hops
• -s count — Time stamp for count hops
• -j host-list — Loose source route along host-list
• -k host-list — Strict source route along host-list
• -w timeout — Time-out in milliseconds to wait for each reply

ROUTE

• -f — Clears the routing tables of all gateway entries. If this parameter is used with one of the commands, the tables are cleared before the command is run.
• command — Specifies one of the four commands:
• PRINT — Prints a route
• ADD — Adds a route
• DELETE — Deletes a route
• CHANGE — Modifies an existing route
• -p — When used with the PRINT command, -p displays the list of registered persistent routes. When used with the ADD command, -p makes a route persistent across boots of the system. (By default, routes aren’t preserved when the system is restarted.) This parameter is ignored for all other commands, which always affect the appropriate persistent routes.
• destination — Specifies the host.
• MASK — If the MASK keyword is present, the next parameter is interpreted as the netmask parameter.
• netmask — If provided, specifies a subnetwork mask value to be associated with this route entry. If not specified, it defaults to 255.255.255.255.
• gateway — Specifies the gateway.
• METRIC — Specifies the metric/cost for the destination.

SNMP

• Reports special events, such as traps, to multiple hosts
• Responds to requests for information from multiple hosts
• Can be set up on any system running NT and TCP/IP
• Sets up special counters in Performance Monitor that can be used to monitor the TCP/IP performance related to SNMP
• Uses host names and IP addresses to recognize the hosts from which it receives and requests information


The SNMP service can be installed for the following reasons:


• To monitor TCP/IP with Performance Monitor
• To monitor an NT-based system with a third-party application
• To set up your computer as an SNMP agent

WINDOWS NT-SPECIFIC UTILITIES

• Event Log
• IPCONFIG
• NBTSTAT
• TRACERT

Event Log

• Errors — Symbolized by stop signs, errors indicate the failure of an NT component or device (or its inability to start). These errors are common on notebook computers when NT fails to start the network components because PCMCIA network cards aren’t present.
• Warnings — Symbolized by exclamation points, warnings indicate an impending problem. Low disk space on a partition triggers a warning, for example.
• Information — Symbolized by the traditional “I” in a blue circle, information events aren’t problems but are still somehow significant. Browser elections often cause information events.

• Success audits — Symbolized by a key, success audits indicate successful security access.
• Failure audits — Symbolized by a padlock, failure audits indicate unsuccessful security access.