Troubleshooting Network Infrastructure © 2004 Cisco Systems, Inc. All rights reserved. IPTT v Troubleshooting Data Network Infrastructure

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Troubleshooting Data Network Infrastructure: Objectives Upon completing this lesson, you will be able to: List common voice issues caused by Data Network Infrastructure problems Explain the difference between routing and switching and list the commands useful in displaying interface and host information Explain VLAN usage in an AVVID network and list the configuration and verification commands required to fully implement VLANs in Cisco IOS Explain the reasons for separating traffic into an auxiliary and native VLAN and list the configuration and verification commands to implement auxiliary and native VLANs Evaluate how IP Routing configuration can impact device registration and call setup Describe how multicast configuration issues can affect music on hold and list the commands used to troubleshoot MOH

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Outline Overview Impact of Data Network Switching Configuration Auxiliary VLANs Router Configuration Multicast Routing Summary Quiz

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Impact of Data Network Applications (VMail, IVR, ICD,...) Headquarters Branch A Branch B CallManager Cluster SRST-Enabled Router SRST-Enabled Router Gatekeeper PSTN IP WAN

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Switching

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Trunking VLAN 1VLAN 3VLAN 2 VLAN 1VLAN 3 Catalyst 3550 XL Switch ISL Trunk Catalyst 3550 XL Switch Catalyst 6500 Series Switch

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v VLAN Routing Router(config)# interface FastEthernet0/0.1 Router(config-subif)# encapsulation dot1Q 1 native Router(config-subif)# ip address Router(config-subif)# ip helper-address Router(config)# interface FastEthernet0/0.2 Router(config-subif)# encapsulation dot1Q 2 Router(config-subif)# ip address Router(config-subif)# ip helper-address IOS-Switch(config)# interface FastEthernet0/1 IOS-Switch(config-if)# switchport trunk encapsulation dot1q IOS-Switch(config-if)# switchport trunk native vlan 1 IOS-Switch(config-if)# switchport mode trunk IOS-Switch(config-if)# switchport trunk allowed vlan all Catalyst6500> (enable) set trunk 3/1 nonegotiate dot1q Set-Based Switch Cisco IOS Switch Cisco Router

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Verifying VLAN Routing IOS-Switch> show int fastEthernet 0/1 switchport Name: Fa0/1 Switchport: Enabled Administrative mode: trunk Operational Mode: trunk Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: dot1q Negotiation of Trunking: Disabled Access Mode VLAN: 0 ((Inactive)) Trunking Native Mode VLAN: 1 Catalyst6500> show trunk * - indicates vtp domain mismatch Port Mode Encapsulation Status Native vlan /1 on dot1q trunking 1 Set-Based Switch Cisco IOS Switch Use the show vlans and show interface commands on the Cisco router to verify interVLAN routing configuration.

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Auxiliary VLANs Native VLAN – Subnetwork 1 Auxiliary VLAN – Subnetwork 3 Data VLAN – Subnetwork 2

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Configuring Auxiliary VLANs IOS-Switch(config)# interface FastEthernet0/1 IOS-Switch(config-if)# switchport trunk encapsulation dot1q IOS-Switch(config-if)# switchport trunk native vlan 1 IOS-Switch(config-if)# switchport mode trunk IOS-Switch(config-if)# switchport voice vlan 222 IOS-Switch(config-if)# spanning-tree portfast IOS-Switch(config-if)# switchport mode trust Catalyst6500> (enable) set port auxiliaryvlan 2/ Auxiliaryvlan 222 configuration successful. Set-Based Switch Cisco IOS Switch

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Verifying Auxiliary VLANs Verify that CDP is enabled on switch ports connected to IP Phones. Use the show port, show vlan, and show cdp neighbors commands to troubleshoot problems with auxiliary VLANs.

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Routing and the Routing Table Network A Network B Routing Table Network A …. …. …. … Network B …. …. …. … Net B …. …. …. … Router 1 Router 4 Router 5 Router 2 Router 3

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v The ping Command IP ping Test Characters CharacterDescription !Each exclamation point indicates receipt of an ICMP echo reply.Each period indicates a timeout while waiting for an ICMP echo reply UA destination unreachable error PDU was received. This normally occurs when a router is advertising a summary route to the requested destination, but the router(s) advertising the summary route doesnt have the complete route to the destination. This is also often returned when an access list in the path is blocking ICMP traffic. QSource quench (destination too busy) MCould not fragment ?Unknown packet type &Packet lifetime exceeded

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Extended Ping Mode TPA2620_HQ#ping Protocol [ip]: Target IP address: Repeat count [5]: 10 Datagram size [100]: 500 Timeout in seconds [2]: 4 Extended commands [n]: y Source address or interface: Type of service [0]: Set DF bit in IP header? [no]: Validate reply data? [no]: Data pattern [0xABCD]: Loose, Strict, Record, Timestamp, Verbose[none]: Sweep range of sizes [n]: Type escape sequence to abort. Sending 10, 500-byte ICMP Echos to , timeout is 4 seconds: !!!!!!!!!!

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Verifying the IP Routing Table TPA2620_HQ#sh ip route Codes: C – connected, S – static, I – IGRP, R – RIP, M – mobile, B – BGP D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2 E1 – OSPF external type 1, E2 – OSPF external type 2, E – EGP I – IS-IS, L1 – IS-IS level-1, L2 – IS-IS level-2, ia – IS-IS inter area C /24 is directly connected, Serial0/0.12 O /24 [110/128] via , 03:29:35, Serial0/0.12 [110/128] via , 03:29:35, Serial0/0.23 O /24 [110/128] via , 03:29:35, Serial0/ /24 is subnetted, 9 subnets O [110/65] via , 03:29:36, Serial0/0.23 O [110/129] via , 03:29:36, Serial0/ /24 is subnetted, 12 subnets O [110/65] via , 03:29:37, Serial0/0.12 O [110/65] via , 03:29:39, Serial0/ O /24 [110/128] via , 03:29:40, Serial0/0.23

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Verifying a Specific Route TPA2620_HQ#sh ip route Routing entry for /24 Known via "ospf 100", distance 110, metric 129, type intra area Last update from on Serial0/0.23, 03:30:24 ago Routing Descriptor Blocks: * , from , 03:30:24 ago, via Serial0/0.23 Route metric is 129, traffic share count is 1

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v The traceroute Command TPA2620_BR#trace Tracing the route to msec 5 msec 4 msec msec 5 msec 4 msec msec 4 msec 4 msec

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Verifying That Access Lists Are Not the Problem ! access-list 101 permit tcp any any eq telnet access-list 101 permit tcp any any eq 2000 ! interface Serial0/0 ip address ip access-group 101 out encapsulation frame-relay frame-relay map ip broadcast ! interface FastEthernet0/0 ip address !

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Verifying That NAT Is Not the Problem interface Serial0/0 ip address ip nat outside ! interface FastEthernet0/0 ip address ip nat inside full-duplex ! ip nat pool NATPOOL prefix-length 23 ! ip nat inside source list NAT_INSIDE pool NATPOOL ! ip access-list extended NAT_INSIDE permit ip any !

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Multicast Routing Multicast and unicast audio sources: Multicast music on hold conserves system resources. Multicast allows multiple users to use the same audio source stream to provide music on hold. Multicast audio sources associate with an IP address. Multicast entails managing devices, IP addresses, and ports.

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Summary Routers and switches and their interconnecting links provide the physical infrastructure needed to transport VoIP traffic. Tools for troubleshooting UP routing problems include the following commands: ping, traceroute, show ip route, and debug ip nat. You configure VLANs on switches on a port-by-port basis. Until recently, a switch port was either dedicated to a single VLAN or trunked (all VLANs). Recognizing the need for a limited function trunk, Cisco developed support for auxiliary VLANs.

© 2004 Cisco Systems, Inc. All rights reserved. IPTT v Lesson Review 1. Which of these statements best defines the purpose of router dial peer statements? 2. If you see the status message FastEthernet 1/0 is down, line protocol is down on a 6500 series switch, what is the likely cause? 3. In order to perform an extended ping, which command is necessary? 4. In order to support auxiliary VLANs, what should you configure on the switch? 5. Which two of these modes are valid switch trunk modes?