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The CSR1000V-Router has already been prepared (Create a CSR1000V-Instance with nested Virtualiation support) and in (Part 4: Package the Service-VM into an OVA) we copied the OVA-Image of our „ubuntu-server“-VM to this Router. Add the internal Network-Interface between Router and Service-VM Install the Service-VM Activate the installed Service-VM Access the VM using the (virtual) Serial-Console Logout: 3x [CTRL]+ Access the VM using SSH via the internal Network Check the local python/NAPALM-Setup to get facts about the containing routerRead More →

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Create the „Ubuntu Server“-VM using KVM on top of the „Ubuntu Desktop“-VM Run the „Virtual Machine Manager“ Create a new virtual Machine: (1) Create a new virtual Machine (2) Select the Installation ISO * and deselect „auto OS Detection“ (3) Choose Memory and CPU Settings (4) Create a virtual Hard-Disk for the VM (5) Give a name to the VM Boot the KVM-VM („Ubuntu Server“) Basic Setup: Language: Englisch my territory: other/Europe/Germany locale: en_US.UTF_8 Keyboard: German hostname: ubuntu-server user / password no home-directory encryption timezone Europe/Berlin use entire virtual disk (no need for „LVM…“ i think) no HTTP-Proxy no automatic updates [x] SSH-Server install GRUBRead More →

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In Configure RMON Alarms&Events by script I’ve shown a short python-algorithm to to discover all Cisco class-based QoS (cbQoS) packet-/drop-counters and to generate RMON-alarms for each. The router monitors these counters every 300s, calculates the delta for the interval and raises RMON-events when there were packets/drops or when the have been before but not anymore. This RMON-event has been configured as an syslog-message to an syslog-receiver etc. The existing script just generated a list of cli-commands which had to be entered manually to the router-config. Not a valid aproach when having hundreds devices to be configured. Now i want the script to automatically configure theRead More →

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Works out of the box. if you’re fine with AES128-Encryption. AES256 might not be a requirement in all cases, but having the opportunity to choose seems to be not absolutely absurd in 2017… Good news: The NetSNMP-AES192/256-patch is on the way. EasySNMP installation and usage I’d like to refer to Linux: SNMP with Python for the basics. IOS-Config: VIEW/GROUP/USER Take the opportunity and leverage SMP-Views to limit access to several SNMP-OIDs. EasySNMP: „Session“-Object with SNMPv3-Credentials Find the official docs here: EasySNMP Session-API Security level could be: no_auth_or_privacy If you want to use the user-based authentication without need for security auth_without_privacy Authentication only might be „goodRead More →

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Today I’ll show how retrieve additional details from already discoverd QoS-Counters. They are mostly descriptive, for human eyes. The „Traffic-Direction“-Attribute might be relevant since in most cases only outbound drop-counters might be interesting, so the discovered list of OIDs could get filtered to process only those outbound OIDs. Refresh: Retrieve all „QoS Packet-Counters“ There are two Policy-Objects #P: Policy #18 Policy #34 Both Policy-Objects contain three Traffic-Classes #Q: Class #65535 Class #131072 Class #196608 Attributes of a bound Policy #P Each Policy has at least two attributes: Interface-Type of the Policy (5 : CoPP) 1:mainInterface 2:subInterface 3:frDLCI 4:atmPVC 5:controlPlane 6:vlanPort 7:evc Traffic-Direction 1:input 2:output InterfaceRead More →

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Discover the OIDs representing the counter-values of all active traffic-classes Ciscos „SNMP Object Navigator“ (http://mibs.cloudapps.cisco.com/ITDIT/MIBS/servlet/index) is our friend to get the base-OID when you know the name of the MIB: Object-NAME <=> Object-ID (OID) „cbQosCMStatsEntry“ <=> „1.3.6.1.4.1.9.9.166.1.15.1.1“ Each object is a set of all counters from „show policy-map interface“-command, the Object Navigator documents the ID of these counters, too.Read More →

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RMON Refresher Think about this given Router-Configuration: Three Queues at interface Gig1: CM_VOIP_RTP CM_VOIP_CTRL class-default with per-Queue-Statistics: Packet counters Drop-counters etc. In these first examples, i don’t want to wait for queue-drops, i’ll just generate DSCP=EF-Traffic by the ping-command and watch the Queue-Packet-Counters, not Drops. Configure RMON Alarms and Events I’ll add two RMON-Events event #10 = rising-threshold – in my example: >1 Packet has been dropped forwarded event #11 = the falling-threshold – no packets have been… Than, instruct the Router to have a look at a QoS-counter: In the upcoming post I’ll discover the RMON-MIB to illustrate where the „enterprise.9….65536“-Parameter comes from. ThisRead More →

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Stop frequent polling of everything, please! Last week I had to troubleshoot a network of a customer which was overwhelmed with SNMP-Queries – it wasn’t the first one. All Switch- and Router-CPUs have been at high level, since every tiny counter was polled at high rate. To provide real-time graphs to the top-level-management. Which hopefully don’t waste time to watch these colourful pictures all day for entertainment purposes. Doesn’t anybody remember RMON? Years ago I’ve been teaching routing&switching-classes as a full-time Cisco/BayNetworks/Fluke-instructor, and in every switching class there was a brief explanation about SNMP. And about RMON. RFC2819 – RMON (Remote Network Monitoring) MIB 4Read More →

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Background: I plan to design and implement a controller-based QoS-Solution with distributed control-plane using SNMP and RMON. How to send SNMP-Requests in Python? Why Python? It’s an arbitrary decision, every programming language might be sufficient. For the moment, I prefer Python for new projects. I decided to try Easy-SNMP, since good performance and a nice python-programming-interface seem to be killer-features for me. EasySNMP homepage EasySNMP documentation A development environment clone an ubuntu-server VM https://allones.de/2017/11/17/linux-quick-and-…ab-vm-deployment/ install net-snmp sudo apt-get install libsnmp-dev snmp-mibs-downloader install gcc, python sudo apt-get install gcc python-dev python-pip install EasySNMP pip install easysnmp Enable SNMP on a Router Never ever enable SNMP-Access forRead More →