This chapter describes how to configure the TCP/IP Host Services (TCP/IP Host) protocol and how to use the TCP/IP Host configuration commands. The chapter includes the following sections:
See "TCP/IP Host Services (Bridge-Only Management)" if you want to know more about why you would use TCP/IP host services.
Do not use this chapter if you are configuring the device for IP routing; instead, refer to "Using IP".
| Note: | To configure Host services, you cannot have any IP address configured on the interfaces. The device cannot be configured as a router for IP. The Host services are for bridging only. |
To access the TCP/IP Host configuration environment, enter the following command at the Config> prompt:
Config> protocol hst TCP/IP-Host Services user configuration TCP/IP-Host Config>
The following sections describe the basic configuration procedures for enabling TCP/IP Host Services on your 2210.
To minimally configure TCP/IP Host services, assign the 2210 an IP address by using the set ip-host command. This IP address is associated with the 2210 as a whole, instead of being associated with a single interface.
Use the enable services command to enable TCP/IP Host Services.
The 2210 uses its default gateway to communicate with hosts and gateways that are not on the bridged network to which the 2210 is directly connected. The 2210 can dynamically learn its default gateway using either ICMP Router Discovery (see the enable router-discovery command in this chapter) or RIP (see the enable rip-listening command in this chapter). You can also statically specify one or more default gateways by using the add default gateway command. The 2210 uses only one default gateway at a time; any additional default gateways are used for backup.
To save the assigned IP address and default gateway information,
This section describes the TCP/IP Host configuration commands. The TCP/IP Host configuration commands allow you to specify network parameters for the TCP/IP Host bridge. Restart the device to activate the configuration commands.
| Note: | The TCP/IP host configuration commands are not effective immediately. They remain pending until you restart or reload the device. |
Table 16. TCP/IP Host Configuration Commands Summary
| Command | Function |
|---|---|
| ? (Help) | Displays all the commands available for this command level or lists the options for specific commands (if available). See "Getting Help". |
| Add | Adds a default-gateway. |
| Delete | Deletes a default-gateway. |
| Disable | Disables TCP/IP Host Services, router-discovery processes, and RIP listening. |
| Enable | Enables TCP/IP Host Services, router-discovery processes, and RIP listening. |
| List | Lists the current TCP/IP Host configuration. |
| Set | Sets the 2210's IP address. |
| Exit | Returns you to the previous command level. See "Exiting a Lower Level Environment". |
The TCP/IP host configuration (Talk 6) commands are not effective immediately. They remain pending until you issue the reload or restart command.
Use the add command to add default gateways (that is, routers) to your configuration.
Default gateways are used when trying to send packets to IP destinations that are off the local subnet. The routing table is then built up through redirect processing. An attempt is made to detect routers that disappear. If the 2210 has booted over the network (via TFTP/BootP), then the default gateway is configured using the information from the booting process.
Syntax:
Example: add default-gateway
Default-Gateway address [0.0.0.0]? 123.45.67.89
Use the delete command to delete default gateways from your 2210 configuration. Enter the IP address of the default gateway you want to remove after the delete command.
Syntax:
Example: delete default-gateway
Enter address to be deleted [0.0.0.0]? 123.45.67.89
Use the disable command to disable the following TCP/IP functions:
Syntax:
Example: disable rip-listening
Example: disable router-discovery
Example: disable services
Use the enable command to enable the following TCP/IP functions:
Syntax:
Example: enable rip-listening
Example: enable router-discovery
Example: enable services
Use the list command to display information about the current TCP/IP Host configuration.
Syntax:
Example: list
TCP/IP-Host config>list
TCP/IP Host SERVICES : enabled
IP-HOST Address : 128.185.142.1
Mask : 255.255.255.0
DEFAULT-GATEWAY Address : 128.185.142.47
RIP-LISTENING : disabled
ROUTER-DISCOVERY : enabled
TCP/IP-Host config>
| TCP/IP Host SERVICES | Displays whether TCP/IP Host SERVICES is enabled or disabled. |
| IP-HOST Address | Displays the current IP-HOST Address. |
| IP-HOST Mask | Displays the current IP-HOST Mask. |
| DEFAULT-GATEWAY Address | Displays the current DEFAULT-GATEWAY Address. |
| RIP-LISTENING | Displays whether RIP-LISTENING is enabled or disabled. |
| ROUTER DISCOVERY | Displays whether ROUTER DISCOVERY is enabled or disabled. |
Use the set command to set the 2210's IP address. You must assign the 2210 an IP address before enabling TCP/IP Host Services.
| Note: | If the IP address is not already configured, it is set (by default) using boot information. This process applies only if the 2210 is a network host operating as an IP host. |
Syntax:
Example: set ip 123.45.67.89
Address mask [255.255.0.0]? IP-Host Address set.
This section describes how to monitor the TCP/IP Host Services on the IBM 2210.
To access the TCP/IP Host monitoring environment, enter the following command at the + (GWCON) prompt:
+ protocol hst TCP/IP-Host>
This section describes the TCP/IP Host monitoring commands. These
commands allow you to view parameters and enter information requests from the
active terminal. Enter these commands at the TCP/IP-Host>
prompt. Table 17 shows the commands.
Table 17. TCP/IP Host Monitoring Commands Summary
| Command | Function |
|---|---|
| ? (Help) | Displays all the commands available for this command level or lists the options for specific commands (if available). See "Getting Help". |
| Dump | Displays the current IP routing table. One line is printed for each destination. |
| Interface | Displays the IBM 2210's IP address. |
| Ping | Continuously pings a given destination, printing a line for each response received. |
| Traceroute | Displays the hop-by-hop route to a given destination. |
| Routers | Displays the list of all IP routers known to the 2210. |
| Exit | Returns you to the previous command level. See "Exiting a Lower Level Environment". |
Use the dump command to display the current IP routing table. One line is printed for each destination. Many of the entries that are displayed are the result of ICMP redirects.
Syntax:
Example:
TCP/IP Host> dump
Type Dest net Mask Cost Age Next hop(s)
Stat 0.0.0.0 00000000 0 51 128.185.142.47
Dir* 128.185.142.0 FFFFFF00 1 50 BDG/0
Default gateway in use.
Type Cost Age Next hop
Stat 0 51 128.185.142.47
Routing table size: 768 nets (52224 bytes), 2 nets known
0 nets hidden, 0 nets deleted, 0 nets inactive
0 routes used internally, 766 routes free
| Type | Route type which indicates how the route was derived:
|
| Dest net | Displays the IP address of the destination network/subnet. |
| Mask | Displays the IP address mask. |
| Cost | Displays the Route Cost. |
| Age | For RIP routes displays the time, in seconds, since the route was refreshed. For other types of routes displays the time, in seconds, since the route was installed. |
| Next Hop | Displays the IP address of the next device on the path toward the destination host. Also displayed is the interface type used by the sending device to forward the packet. |
| Default gateway | Displays the IP address of the default gateway along with the route type, cost, age, and next hop information associated with that entry. |
| Routing table size | Displays the current size (in networks and bytes) of the current table. Also identifies the number of networks (nets) known to the host. |
Use the interface command to display the IBM 2210's IP address. When TCP/IP Host Services are running over the bridge, a single address is displayed on the terminal as Bridge/0.
Syntax:
Example:
TCP/IP Host> interface Interface MTU IP Address(es) Mask(s) Address-MTU BDG/0 1500 128.185.142.16 255.255.255.0 Unspecified
| Interface | Displays the type of interface. For TCP/IP Host Services, this is always BDG/0, indicating the bridge. |
| IP Address | Displays the IP address of the TCP/IP Host Services interface. |
| Mask | Displays the IP address subnet mask. |
Use the ping command to make the device send ICMP Echo Requests to a given destination once a second ("pinging") and watch for a response. This command can be used to isolate trouble in an internetwork environment.
This process is done continuously, incrementing the ICMP sequence number with each additional packet. Matching received ICMP Echo responses are reported with their sequence number and the round trip time. The granularity (time resolution) of the round trip time calculation is platform-specific, and usually is around 20 milliseconds.
To stop the pinging process, type any character at the terminal. At that time, a summary of packet loss, round trip time, and number of unreachable ICMP destinations will be displayed.
When a multicast address is given as destination, there may be multiple responses printed for each packet sent, one for each group member. Each returned response is displayed with the source address of the responder.
The size of the ping (number of data bytes in the ICMP message, excluding the ICMP header), TTL value, and rate of pinging are all user-configurable. The default values are a size of 56 bytes, a TTL of 64, and a rate of 1 ping per second.
Syntax:
Example:
TCP/IP Host> ping Destination IP address [0.0.0.0]? 128.185.142.11 Source IP address [128.185.142.16]? Ping data size in bytes [56]? Ping TTL [64]? Ping rate in seconds [1]? PING 128.185.142.16 -> 128.185.142.11: 56 data bytes, ttl=64, ... every 1 sec. 56 data bytes from 128.185.142.11: icmp_seq=0. ttl=254. time=0. ms 56 data bytes from 128.185.142.11: icmp_seq=1. ttl=254. time=0. ms 56 data bytes from 128.185.142.11: icmp_seq=2. ttl=254. time=0. ms 56 data bytes from 128.185.142.11: icmp_seq=3. ttl=254. time=0. ms 56 data bytes from 128.185.142.11: icmp_seq=4. ttl=254. time=0. ms 56 data bytes from 128.185.142.11: icmp_seq=5. ttl=254. time=0. ms ----128.185.142.11 PING Statistics---- 6 packets transmitted, 6 packets received, 0% packet loss round-trip min/avg/max = 0/0/0 ms
Use the traceroute command to display the entire path to a given destination, hop by hop. For each successive hop, the traceroute command sends out three probes and prints the IP address of the responder along with the round trip time associated with the response. If a particular probe receives no response, an asterisk (*) is printed. Each line in the display relates to this set of three probes, with the left-most number indicating the distance from the device executing the command (in network device hops).
The traceroute is complete when the destination is reached, an ICMP Destination Unreachable message is received, or the path length reaches 32 network device hops.
Syntax:
Example:
TCP/IP Host> traceroute Destination IP address [0.0.0.0]? 128.185.144.239 Source IP address [128.185.142.16]? Data size in bytes [56]? Number of probes per hop [3]? Wait time between retries in seconds [3]? Maximum TTL [32]? TRACEROUTE 128.185.142.16 -> 128.185.144.239: 56 data bytes 1 128.185.142.11 16 ms 0 ms 0 ms 2 128.185.143.33 16 ms 0 ms 0 ms 3 128.185.144.239 16 ms 0 ms 0 ms
In the display:
| TRACEROUTE | Displays the destination area address and the size of the packet being sent to that address. |
| 1 | The first trace showing the destination's NSAP and the round trip time it took the packet to reach the destination and return. The packet is traced three times. |
| Destination unreachable | Indicates that no route to the destination is available. |
| 1 * * * 2 * * * | Indicates that the device is expecting some form of response from the destination, but the destination is not responding. |
When a probe receives an unexpected result (see the previous output
example), several indicators can be printed. These indicators are
explained in the following table.
| !N | Indicates that an ICMP Destination Unreachable (net unreachable) has been received. |
| !H | Indicates that an ICMP Destination Unreachable (host unreachable) has been received. |
| !P | Indicates that an ICMP Destination Unreachable (protocol unreachable) has been received. |
| ! | Indicates that the destination has been reached, but the reply sent by the destination has been received with a TTL of 1. This usually indicates an error in the destination, prevalent in some versions of UNIX, whereby the destination is inserting the probe's TTL in its replies. This unfortunately leads to a number of lines consisting solely of asterisks before the destination is finally reached. |
Use the routers command to display the list of all IP routers that are known to the IBM 2210. Routers can be learned through:
Each router is listed with its origin, its priority (used when selecting the default route), and its lifetime (the number of seconds before the router will be declared invalid unless it is heard from again).
Syntax:
Example: routers