Chapter 13 Enabling the FDP and Reading Cisco Discovery Protocol (CDP) Packets

Transcription

1 Chapter 13 Enabling the FDP and Reading Cisco Discovery Protocol (CDP) Packets Using FDP FDP enables HP Routing Switches to advertise themselves to other HP Routing Switches on the network. When you enable FDP on an HP device, the device periodically advertises information including the following: Hostname (device ID) Product platform and capability Software version VLAN and Layer 3 protocol address information for the port sending the update. IP, IPX, and AppleTalk Layer 3 information is supported. An HP device running FDP sends FDP updates on Layer 2 to MAC address 01-E0-52-CC-CC-CC. Other HP devices listening on that address receive the updates and can display the information in the updates. HP devices can send and receive FDP updates on Ethernet. FDP is disabled by default. NOTE: If FDP is not enabled on an HP device that receives an FDP update or the device is running a software release that does not support FDP, the update passes through the device at Layer 2. Configuring FDP The following sections describe how to enable FDP and how to change the FDP update and hold timers. Enabling FDP Globally To enable an HP device to globally send FDP packets, enter the following command at the global CONFIG level of the CLI: HP9300(config)# fdp run Syntax: [no] fdp run The feature is disabled by default. Enabling FDP at the Interface Level Starting in software release , you can enable FDP at the interface level by entering commands such as the following: HP9300(config)# int e 2/1 13-1

2 Installation and Basic Configuration Guide HP9300(config-if-2/1)# fdp enable Syntax: HP9300HP9300[no] fdp enable By default, the feature is enabled on an interface once FDP is enabled on the device. Changing the FDP Update Timer By default, an HP device enabled for FDP sends an FDP update every 60 seconds. You can change the update timer to a value from seconds. To change the FDP update timer, enter a command such as the following at the global CONFIG level of the CLI: HP9300(config)# fdp timer 120 Syntax: [no] fdp timer <secs> The <secs> parameter specifies the number of seconds between updates and can be from seconds. The default is 60 seconds. Changing the FDP Hold Time By default, an HP device that receives an FDP update holds the information until one of the following events occurs: The device receives a new update. 180 seconds have passed since receipt of the last update. This is the hold time. Once either of these events occurs, the device discards the update. To change the FDP hold time, enter a command such as the following at the global CONFIG level of the CLI: HP9300(config)# fdp holdtime 360 Syntax: [no] fdp holdtime <secs> The <secs> parameter specifies the number of seconds an HP device that receives an FDP update can hold the update before discarding it. You can specify from seconds. The default is 180 seconds. Displaying FDP Information You can display the following FDP information: FDP entries for HP neighbors Individual FDP entries FDP information for an interface on the device you are managing FDP packet statistics NOTE: If the HP device has intercepted CDP updates, then the CDP information is also displayed. 13-2

3 Enabling the FDP and Reading Cisco Discovery Protocol (CDP) Packets Displaying Neighbor Information To display a summary list of all the HP neighbors that have sent FDP updates to this HP device, enter the following command: HP9300A# show fdp neighbor Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater (*) indicates a CDP device Device ID Local Int Holdtm Capability Platform Port ID HP 9300 seriesb Eth 2/9 178 Router HP 9300 series Rou Eth 2/9 Syntax: show fdp neighbor [ethernet <portnum>] [detail] The ethernet <portnum> parameter lists the information only for updates received on the specified interface. The detail parameter lists detailed information for each device. The show fdp neighbor command, without optional parameters, displays the following information. Table 13.1: Summary FDP and CDP Neighbor Information This Line... Device ID Local Int Holdtm Capability Platform Port ID Displays... The hostname of the neighbor. The interface on which this HP device received an FDP or CDP update for the neighbor. The maximum number of seconds this device can keep the information received in the update before discarding it. The role the neighbor is capable of playing in the network. The product platform of the neighbor. The interface through which the neighbor sent the update. To display detailed information, enter the following command: HP9300A# show fdp neighbor detail Device ID: HP 9300 seriesb configured as default VLAN1, tag-type8100 Platform: HP 9300 series Router, Capabilities: Router Interface: Eth 2/9 Port ID (outgoing port): Eth 2/9 is TAGGED in following VLAN(s): Holdtime : 176 seconds HP Version b1T53 Compiled on Aug at 10:35:21 labeled as H2R07601b1 13-3

4 Installation and Basic Configuration Guide The show fdp neighbor detail command displays the following information. Table 13.2: Detailed FDP and CDP Neighbor Information This Line... Device ID Entry address(es) Platform Capabilities Interface Port ID Holdtime Version Displays... The hostname of the neighbor. In addition, this line lists the VLAN memberships and other VLAN information for the neighbor port that sent the update to this device. The Layer 3 protocol addresses configured on the neighbor port that sent the update to this device. The product platform of the neighbor. The role the neighbor is capable of playing in the network. The interface on which this HP device received an FDP or CDP update for the neighbor. The interface through which the neighbor sent the update. The maximum number of seconds this device can keep the information received in the update before discarding it. The software version running on the neighbor. Displaying FDP Entries To display the detailed neighbor information for a specific device, enter a command such as the following: HP9300A# show fdp entry HP 9300 seriesb Device ID: HP 9300 seriesb configured as default VLAN1, tag-type8100 Platform: HP 9300 series Router, Capabilities: Router Interface: Eth 2/9 Port ID (outgoing port): Eth 2/9 is TAGGED in following VLAN(s): Holdtime : 176 seconds HP Version b1T53 Compiled on Aug at 10:35:21 labeled as H2R07601b1 Syntax: show fdp entry * <device-id> The * <device-id> parameter specifies the device ID. If you enter *, the detailed updates for all neighbor devices are displayed. If you enter a specific device ID, the update for that device is displayed. For information about the display, see Table 13.2 on page Displaying FDP Information for an Interface To display FDP information for an interface, enter a command such as the following: HP9300A# show fdp interface ethernet 2/3 FastEthernet2/3 is up, line protocol is up Encapsulation ethernet Sending FDP packets every 5 seconds Holdtime is 180 seconds 13-4

5 Enabling the FDP and Reading Cisco Discovery Protocol (CDP) Packets This example shows information for Ethernet port 2/3. The port sends FDP updates every 5 seconds. Neighbors that receive the updates can hold them for up to 180 seconds before discarding them. Syntax: show fdp interface [ethernet <portnum>] The ethernet <portnum> parameter lists the information only for the specified interface. Displaying FDP and CDP Statistics To display FDP and CDP packet statistics, enter the following command: HP9300A# show fdp traffic CDP/FDP counters: Total packets output: 6, Input: 5 Hdr syntax: 0, Chksum error: 0, Encaps failed: 0 No memory: 0, Invalid packet: 0, Fragmented: 0 Internal errors: 0 Syntax: show fdp traffic Clearing FDP and CDP Information You can clear the following FDP and CDP information: Information received in FDP and CDP updates FDP and CDP statistics The same commands clear information for both FDP and CDP. Clearing FDP and CDP Neighbor Information To clear the information received in FDP and CDP updates from neighboring devices, enter the following command: HP9300# clear fdp table Syntax: clear fdp table NOTE: This command clears all the updates for FDP and CDP. Clearing FDP and CDP Statistics To clear FDP and CDP statistics, enter the following command: HP9300# clear fdp counters Syntax: clear fdp counters Reading CDP Packets Cisco Discovery Protocol (CDP) packets are used by Cisco devices to advertise themselves to other Cisco devices. By default, HP devices forward these packets without examining their contents. You can configure an HP device to intercept and display the contents of CDP packets. This feature is useful for learning device and interface information for Cisco devices in the network. HP software release 07.5.xx supports intercepting and interpreting CDP version 1 packets. Software release extends CDP support to version 2 packets. In and later, when you enable CDP support, support for both CDP versions is enabled. NOTE: The HP device can interpret only the information fields that are common to both CDP version 1 and CDP version

6 Installation and Basic Configuration Guide NOTE: When you enable interception of CDP packets, the HP device drops the packets. As a result, Cisco devices will no longer receive the packets. Enabling Interception of CDP Packets Globally To enable the HP device to intercept and display CDP packets, enter the following command at the global CONFIG level of the CLI: HP9300(config)# cdp run Syntax: [no] cdp run The feature is disabled by default. Enabling Interception of CDP Packets on an Interface Starting with software release , you can disable and enable CDP at the interface level. You can enter commands such as the following: HP 9300 series(config)# int e 2/1 HP 9300 series(config-if-2/1)# cdp enable Syntax: HP 9300 serieshp 9300 series[no] cdp enable By default, the feature is enabled on an interface once CDP is enabled on the device. Displaying CDP Information You can display the following CDP information: Cisco neighbors CDP entries for all Cisco neighbors or a specific neighbor CDP packet statistics Displaying Neighbors To display the Cisco neighbors the HP device has learned from CDP packets, enter the following command: HP9300# show fdp neighbors Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater (*) indicates a Cisco device Device ID Local Int Holdtm Capability Platform Port ID (*)Router Eth 1/1 124 R cisco RSP4 FastEthernet5/0/0 Syntax: show fdp neighbors [detail ethernet <portnum>] 13-6

7 Enabling the FDP and Reading Cisco Discovery Protocol (CDP) Packets To display detailed information for the neighbors, enter the following command: HP9300# show fdp neighbors detail Device ID: Router IP address: Platform: cisco RSP4, Capabilities: Router Interface: Eth 1/1, Port ID (outgoing port): FastEthernet5/0/0 Holdtime : 150 seconds Cisco Internetwork Operating System Software IOS (tm) RSP Software (RSP-JSV-M), Version 12.0(5)T1, RELEASE SOFTWARE (fc1) Copyright (c) by cisco Systems, Inc. Compiled Thu 19-Aug-99 04:12 by cmong To display information about a neighbor attached to a specific port, enter a command such as the following: HP9300# show fdp neighbors ethernet 1/1 Device ID: Router IP address: Platform: cisco RSP4, Capabilities: Router Interface: Eth 1/1, Port ID (outgoing port): FastEthernet5/0/0 Holdtime : 127 seconds Cisco Internetwork Operating System Software IOS (tm) RSP Software (RSP-JSV-M), Version 12.0(5)T1, RELEASE SOFTWARE (fc1) Copyright (c) by cisco Systems, Inc. Compiled Thu 19-Aug-99 04:12 by cmong Displaying CDP Entries To display CDP entries for all neighbors, enter the following command: HP9300# show fdp entry * Device ID: Router IP address: Platform: cisco RSP4, Capabilities: Router Interface: Eth 1/1, Port ID (outgoing port): FastEthernet5/0/0 Holdtime : 124 seconds Cisco Internetwork Operating System Software IOS (tm) RSP Software (RSP-JSV-M), Version 12.0(5)T1, RELEASE SOFTWARE (fc1) Copyright (c) by cisco Systems, Inc. Compiled Thu 19-Aug-99 04:12 by cmong Syntax: show fdp entry * <device-id> 13-7

8 Installation and Basic Configuration Guide To display CDP entries for a specific device, specify the device ID. Here is an example. HP9300# show fdp entry Router1 Device ID: Router1 IP address: Platform: cisco RSP4, Capabilities: Router Interface: Eth 1/1, Port ID (outgoing port): FastEthernet5/0/0 Holdtime : 156 seconds Cisco Internetwork Operating System Software IOS (tm) RSP Software (RSP-JSV-M), Version 12.0(5)T1, RELEASE SOFTWARE (fc1) Copyright (c) by cisco Systems, Inc. Compiled Thu 19-Aug-99 04:12 by cmong Displaying CDP Statistics To display CDP packet statistics, enter the following command: HP9300# show fdp traffic CDP counters: Total packets output: 0, Input: 3 Hdr syntax: 0, Chksum error: 0, Encaps failed: 0 No memory: 0, Invalid packet: 0, Fragmented: 0 Syntax: show fdp traffic Clearing CDP Information You can clear the following CDP information: Cisco Neighbor information CDP statistics To clear the Cisco neighbor information, enter the following command: HP9300# clear fdp table Syntax: clear fdp table To clear CDP statistics, enter the following command: HP9300# clear fdp counters Syntax: clear fdp counters 13-8