#Cisco mac address table associated vlan software#

The switches configured with SNMPР’В version 3 contain different security levels configuration. The switches are configuredР’В with different SNMP versions in order to test syntax of snmpwalk command used by BASH script.Р’В The SNMP version 2c is configured on the switch with IP address 192.168.1.30 and a version 3 is configured on the rest switches. This part shows configuration of SNMP agents on Cisco switches and an example of using snmpwalk command that is used to query SNMP agents. SNMP Configuration on Switches and SNMPwalk The switchР’В is statically configured with IP address 172.17.100.45/16.Р”Сћ. Thanks to NAT connection the NMS station has connectivity to the network 172.17.0.0/16 where is a Cisco Catalyst 3550 switch located. The IP address of the Ethernet1 interface is 10.0.2.15/24 and it is obtainedР’В automatically from Qemu built-in DHCP serverР’В (subnet 10.0.2.0/24). The cloud device is connected to the subnet 172.17.0.0/16Р’В using NAT created by Qemu. The first interface - Ethernet0 is connected to the subnet 192.168.1.0/24 and it has assigned an IPР’В address 192.168.1.2/24.Р’В The second interface Ethernet1 is connected to a cloud device (РµвЂ¦С“ switch icon labeled with description c3550). The NMS station is occupied with two network interfaces. The hosts obtain IP addresses automatically from DHCPР’В server configured on switch vIOS-L2-1 (192.168.1.1). Switches have their SVI interfaces statically configured with IP address from subnet range 192.168.1.0/24.

Using a hardware switch in the lab is a must as vIOS-L2 instances can only provide infoР’В about hosts connected to VLAN 1. The only exception is a Cisco CatalystР’В 3550 switch that is connected to topology via GNS3 network cloud device.

#Cisco mac address table associated vlan software#

X86-64 Linux Fedora with installed GNS3 1.3.11 and Qemu1.4.0Р”В¬isco vIOS l2 Software (vios_l2-ADVENTERPRISEK9-M), Version 15.2Р”В¬isco Catalyst 3550Р’В (C3550-IPSERVICESK9-M), Version 12.2(55)SE9Р”Р„ll virtual network and host devices are runningР’В inside GNS3 project and they are emulated by Qemu emulator and virtualizer. Network hosts are simulated by Core Linux appliances connected to Cisco vIOS-l2 switches.Р”РЋ.1 List of software used for creating GNS3 lab The topology consists of three Cisco virtual switch appliances running vIOS-L2 and one network management station (NMS) based on Kali Linux. For this purpose I have created a test network labР’В using GNS3. We will configure SNMP version 2c and 3 on Cisco switches and create a BASH script that collects required data for us. If you do the second one, it makes reading the ifAlias much more straight forward, however I have not done this globally.The goal of this article is to introduce a script that automates a process of collectingР’В MAC and IP address of hosts connected to Cisco switches using Simple Network Management Protocol ( SNMP). Set interfaces ge-0/0/36 unit 0 description 'Description on the sub-interface'Р”В«oth are valid, but the GUI only does the first one similarly the GUI only displays the value from the first one. You can, if you are suitably detailed-oriented, apply your port descriptions to the sub-interfaces instead of the interfaces, eg: set interfaces ge-0/0/36 description 'Description on the physical port' My script checks for ifAliases (since on other things like Dells and HPs it will find them) but the Junipers don't have them in the right place. This hoopage-jumpage is necessary because with simpler switches, the ifPort index is the same as the physical port index - ifPort 1 is port 1 on the switch. In this case the mac is associated with 0/0/36.0, while the label is associated with 0/0/36. The second is that on a Juniper the interface the mac address is associated is almost always a sub-interface, and port labels/descriptions are usually associated with the physical interface, so there isn't a trivial way to read the ifLabel off of the port description based on the portID (and glossing over the whole converting ifPort-to-ifIndex) you get back from the Q-Bridge-II.Р”Р‡or example: $ findmac -DEBUG -c MyPass sa4-39 00:07:e9:25:05:3c

So you have to pull in the table and convert base-10 MACs to the base-16 MACs you are used to dealing with. Now you want to beware because there are a couple of wrinkles: firstly the MAC addresses are encoded as row specifications in the OIDs, the VALUES are the ifPort that that MAC address is reachable through.

The OID you want is called the Q-Bridge-II MIB, at 1.3.6.1.2.1.17.7.1.2.2.1.2 - it returns a list of MAC addresses associated with the logical port those MAC addresses are listed on.