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1.3 Configure these network components to support Cisco Collaboration solutions

Updated: Apr 21, 2023

1.3 Configure these network components to support Cisco Collaboration solutions:

  • 1.3.a DHCP

  • 1.3.b NTP

  • 1.3.c CDP

  • 1.3.d LLDP

  • 1.3.e LDAP

  • 1.3.f TFTP

  • 1.3.g Certificates


Cisco Collaboration solutions





DHCP: Dynamic Host Configuration Protocol

  • DHCP is used to automatically assign IP addresses to devices on the network, reducing the need for manual configuration.

  • To configure DHCP, a DHCP server must be set up on the network and the network devices must be configured to obtain their IP addresses dynamically from the DHCP server.

Check out this blog on What is DHCP.


The endpoint will send a DHCP discovery message to the DHCP server. Typically, the DHCP server is a router, but the Cisco Unified Communications Manager, as well as other DHCP server types, can also fulfill this role.

A limitation in using the Cisco Unified Communications Manager is that it allows support for only up to 1000 devices. However, in either case, an option is made available for the TFTP server address to be discovered at the same time.

This option is called Option 150. When the DHCP server receives the DHCP discovery, it responds with a DHCP offer. The DHCP offer includes an IP address, subnet mask, and default gateway address at a minimum.

Additionally, a TFTP server address (with use of Option 150) and possibly one or more DNS addresses can also be provided. The endpoint responds to the DHCP offer with a DHCP request for the specific information sent in the DHCP offer.

The DHCP server will then send a DHCP acknowledgment authorizing the use of the DHCP information exchanged and end the DHCP session.




NTP: Network Time Protocol (time on phone)

  • NTP is used to synchronize the clocks of network devices, ensuring that they all have the same time. This is important for accurate event logging and troubleshooting.

  • To configure NTP, an NTP server must be set up on the network, and the network devices must be configured to obtain their time from the NTP server.

The Cisco Unified Communications Manager uses NTP to obtain time information from a time server; however, only the publisher sends NTP requests to the external NTP server or servers. Subscribers synchronize their time with the publisher.

NTP is a protocol for synchronizing computer system clocks over IP networks.






CDP and LLDP: Cisco Discovery Protocol

  • CDP is a proprietary protocol used by Cisco devices to share information about other directly connected Cisco equipment, including device type, uptime, IOS version, and IP address.

  • To configure CDP, it must be enabled on the network devices, and the devices must be configured to send and receive CDP information.

  • Yes, the IP phone will work even with deactivated CDP if you configure it with the voice VLAN manually. CDP has two primary purposes here: it informs the IP phone about the voice VLAN to be used, and if the phone is required to rewrite the CoS field in the data frames sent by the PC to a specific value, CDP also advertises this CoS value to the phone.

The first communication that the endpoint will send out is a Cisco Discovery Protocol (CDP) frame with a Voice VLAN query to the switch. This CDP communication is used to obtain the Voice VLAN information if no local Voice VLAN ID (VVID) is configured already on the phone. If a non-Cisco phone or non-Cisco switch is used, then the LLDP-MED protocol can be used for the same purpose.

  • LLDP is a vendor-neutral protocol used by network devices to share information about other directly connected network devices, including device type, capabilities, and network policies.

  • To configure LLDP, it must be enabled on the network devices, and the devices must be configured to send and receive LLDP information.

To configure CDP and LLDP, click here for lab




LDAP: Lightweight Directory Access Protocol

  • LDAP is a directory service protocol used to manage and organize user information, such as usernames, passwords, and phone numbers, in a centralized database.

  • To configure LDAP, an LDAP server must be set up and the network devices must be configured to use LDAP for authentication and directory services.

Visit HERE to configure LDAP.




TFTP: Trivial File Transfer Protocol

  • TFTP is a simple file transfer protocol used to transfer configuration and firmware files between network devices and a TFTP server.

  • To configure TFTP, a TFTP server must be set up, and the network devices must be configured to use TFTP for file transfers.

Now that the endpoint has appropriate IP address information and the TFTP server address, it can send a TFTP Get message to the TFTP server. This message is typically sent over HTTP when using current endpoints, but TFTP signaling could be used as well. The communication that the endpoints sent to the TFTP server contains their MAC addresses because that is what the Cisco Unified Communications Manager uses to identify the endpoint’s configuration file.





Certificates

  • Certificates are used to securely identify devices and users in the network, and to encrypt communication traffic.

  • To configure certificates, a certificate authority (CA) must be set up, and the network devices and users must be issued certificates by the CA. The network devices must then be configured to use certificates for authentication and encryption.

The Cisco Unified Communications Manager will first exchange a certificate trust list (CTL) file. The CTL file contains a set of certificates and is used only when Cisco Unified Communications Manager cluster security has been enabled.




In Summary






Resources:








  • Review of Chapter 5

  • Practice Quiz

  • Flashcards

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