Archive for the ‘Network Management’ Category

Monitor QoS Policy on Cisco Router using SNMP

March 23rd, 2017 No comments

This recipe describes how to use SNMP to determine the traffic offered and drop rate for a QoS policy configured on a Cisco router.

The steps here describe which OIDs to interrogate in the CISCO-CLASS-BASED-QOS-MIB


Get the SNMP ifIndex for the interface where the QoS policy is attached:
CiscoRouter#sh snmp mib ifmib ifindex | i GigabitEthernet0/1
GigabitEthernet0/1: Ifindex = 22

(or by using SNMP):
root@Linux# snmpwalk -v2c -c communityname | grep -i GigabitEthernet0/1
RFC1213-MIB::ifDescr.22 = STRING: “GigabitEthernet0/1” Read more…

Categories: CISCO, Network Management, QoS Tags: ,

Batch File to append entry to hosts file on local or remote PC

February 28th, 2014 No comments

These are two small Microsoft Windows batch files which will enable administrators to append entry to hosts file on local or remote PC:

 First determine the computer name:

L00151267 Read more…

Categories: Network Management Tags:

Executing ipconfig and other commands on remote machines

February 25th, 2014 No comments

To execute the “ipconfig /all” command on one or more remote machines you can use the psexec utility that is part of pstools, available from Microsoft. The syntax is: pstools \\machine_name command
For example:

C:\Users\dmatthews\Desktop\pstools>psexec \\L00151270 ipconfig /all

To list just the IP version 4 address, pipe the output throught the ‘find’ command:

C:\Users\dmatthews\Desktop\pstools>psexec \\L00151270 ipconfig /all | find “IPv4” Read more…

Categories: Network Management, Security Tags:

Monotoring Redundant Power Supplies using IPMI Tool and Nagios

April 22nd, 2013 No comments

For SuperMicro motherboards which use IPMI, you can setup monitoring of RPS’s using Nagios and the IPMI plugin.

IPMItool is an open source utility to work with the IPMI management cards in some servers. Depending on your particular Linux distribution, you can probably “apt-get install ipmitool” or “yum install ipmitool” to get it. It is basically a command line tool that can be used instead of the IPMI web interface. Read more…

Categories: Nagios, Network Management Tags:

SNMP version 3 – Wireshark (pcap) Capture

April 2nd, 2013 No comments


Download this capture file:snmp_usm

OR: view it now via Cloudshark

SNMPv3 provides a secure environment for the management of systems covering the following: Read more…

Categories: Network Management Tags:

Forcing DHCP Renewal via Batch File using Pstools

March 10th, 2013 No comments

The challenge was to obtain all user IP addresses in order to locate them on the local LAN (i.e. to locate their switch port by checking arp caches and mac address-table entries in the usual manner).  Once located I needed to place them into a different vlan and then have the user reboot to obtain a new IP address.  How could I accomplish this remotely and by “stealth”.  Read more…

Categories: Network Management Tags:

Network Monitoring for Dummies

April 28th, 2011 No comments

A  nice little introduction to network monitoring (provided by my employer – registration required for obtaining the free download). This book does lean slightly towards using Cascade products to provide monitoring, troubleshooting and analytics – BUT I’m happy to say that it does remain a nice little read for anyone who has an interest in network monitoring. Read more…

Kerberos (RFC1510) Failure Codes

April 18th, 2011 No comments

These failure codes are the original error codes from the Kerberos RFC 1510 Read more…

Categories: Network Management Tags:

Using Network Grep (ngrep.exe) to Capture Traffic. (Filter on Payload!)

July 31st, 2010 No comments

ngrep is a “network grep” utility that can be used to match regular expressions within network packet payloads. This is a very handy utility as many network analysers (“packet sniffers”) can examine the packet header, but either do not display or cannot filter based on packet payload. Read more…

SNMP MIB Persistancy

May 26th, 2010 No comments

SNMP monitoring often references interfaces using the “ifindex”, in order to solicit information.  Sometimes though, the ifindex can change or be slightly different to the actual interface number, for example: Read more…

Categories: Network Management Tags: