Chapter 22 Advanced DHCP Server Properties

Tuning the DHCP Server

•Windows:

–For Tcl—\program files\Network Registrar\extensions\dhcp\tcl

–C or C++—\program files\Network Registrar\extensions\dhcp\dex

It is best to place these extensions in the appropriate directory for TCL or C/C++ extensions. Then, when configuring the filename, just enter the filename itself, without slash (/) or backslash (\).

If you want to place extensions in subdirectories, enter the filename with a path separator. These are different depending on the operating system on which your DHCP server is running.

Note When entering a filename that contains a backslash (\) character in Windows, you must enter it with a double-backslash (\\), because backslash (\) is an escape character in the CLI. For example, enter the filename debug\myextension.tcl as debug\\myextension.tcl.

Step 2 Use the extension command to configure the DHCP server to recognize this extension.

Step 3 Attach the configured extension to one or more DHCP extension points using dhcp attachExtension.

Step 4 Reload the server.

Tuning the DHCP Server

Other helpful hints in tuning your DHCP performance include:

•Set the request (max-dhcp-requests) and response (max-dhcp-responses) buffers for optimal throughput. See Table 22-1 on page 22-4for details.

•Keep the defer-lease-extensionsattribute enabled. This reduces writes to the database.

•Set the last-transaction-time-granularityattribute to at least 60 seconds, optimally a value greater than half your lease interval.

•Disable the allow-lease-time-overrideattribute for policies offering production leases.

•Minimize your logging and debugging settings. If you require logging, use the log-settingsattribute for the DHCP server with a controlled number of attributes, as described in Table 22-2.

Table 22-2 DHCP Log Settings

 

 

 

 

Log Setting

 

 

 

 

 

 

(Numeric Equivalent)

Description

 

 

 

 

 

 

 

 

 

 

default (1)

Displays basic DHCP activity logging (the default setting).

 

 

 

 

 

 

 

 

 

 

incoming-packets (2)

Logs a separate line for each incoming DHCP packet (the default).

 

 

 

 

 

 

 

 

 

 

missing-options (3)

Displays missing policy options expected by a client (the default).

 

 

 

 

 

 

 

 

 

 

incoming-packet-detail (4)

The same as incoming-packets, but in human-readable form.

 

 

 

 

 

 

 

 

 

 

outgoing-packet-detail (5)

Logs each incoming DHCP packet in a human-readable form.

 

 

 

 

 

 

 

 

 

 

unknown-criteria (6)

Logs whenever a client entry has a selection-criteriaor

 

 

 

 

 

selection-criteria-excludedthat is not found in any scope appropriate for

 

 

 

 

 

that client’s current network location.

 

 

 

 

 

 

 

 

 

 

dns-update-detail (7)

Logs each sent and replied DNS update.

 

 

 

 

 

 

 

 

 

 

Cisco CNS Network Registrar User’s Guide

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

22-10

 

 

 

OL-6240-02

 

 

 

 

 

 

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Cisco Systems OL-6240-02 manual Tuning the Dhcp Server, 22-10
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OL-6240-02 specifications

Cisco Systems OL-6240-02 is a highly regarded certification exam that delves into the realm of enterprise networking, particularly focusing on the Cisco Certified Network Professional (CCNP) Routing and Switching track. This particular exam serves as a critical test for network professionals aiming to validate their skills and knowledge in advanced routing technologies and network design.

One of the main features of OL-6240-02 is its emphasis on in-depth understanding of IP routing principles. Candidates are expected to demonstrate proficiency in configuring, maintaining, and troubleshooting complex routing protocols like OSPF (Open Shortest Path First), EIGRP (Enhanced Interior Gateway Routing Protocol), and BGP (Border Gateway Protocol). This includes comprehending routing algorithms, path selection, and the implementation of route redistribution, which are essential for optimizing network performance.

The exam also covers the characteristics of network security and infrastructure, where candidates must exhibit knowledge of implementing security protocols and best practices to safeguard network communications. This includes configuring virtual private networks (VPNs), utilizing access control lists (ACLs), and applying encryption techniques to secure data in transit.

Another crucial technology tested in OL-6240-02 is Quality of Service (QoS). Professionals must be adept at configuring QoS mechanisms to prioritize traffic, ensuring that critical applications receive the necessary bandwidth and latency requirements. This is increasingly important as businesses rely on a multitude of applications that have varying performance needs.

Cisco's emphasis on network automation and programmability is also a focal point of this certification. Candidates are expected to be familiar with using Cisco's software-defined networking (SDN) solutions and automation tools, which are essential for modern network management. This involves understanding how to leverage APIs and modeling tools to streamline network operations and enhance efficiency.

To succeed in OL-6240-02, candidates should possess a solid foundation in network fundamentals and have hands-on experience with Cisco devices. The certification not only validates expertise but also prepares professionals for real-world challenges in designing, implementing, and troubleshooting enterprise networks. Overall, OL-6240-02 is a stepping stone for network professionals seeking higher-level certifications and career advancements in the ever-evolving field of networking.
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