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SPAN mirrors receive or transmit (or both) traffic on one or more source ports to a destination port for analysis. A copy of the packets received or sent by the source interfaces are sent to the destination interfacePrerequisites:Need to understand how optical tap works, here’s some interesting information (ctto) Link:https://community.fs.com/blog/do-you-know-about-optical-tap-test-access-point-cassettes.html https://en.wikipedia.org/wiki/Network_tap#/media/File:Optical-tap-schema-wiki.gif Setup: Cisco Catalyst 4948 2 Routers connected via Optical Tap Network Diagram: : Step 1: Connect physically the links as per above diagram.  Connect UTP cable from switch to…

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Nmap, or short for Network Mapper, is a free and pen-source tool for scanning vulnerabilities and can also be used for network discovery. It can help identify what devices are running on their systems, discovering hosts that are available and the services they running. To see the open ports or running daemon/services in your routers or switches, you can use nmap to test your routers. where: 192.168.1.1 is your router IP Sample1: To scan using default safe scripts nmap -sV…

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There are sample best practice commands that need to be configured in Cisco IOS-XR devices for additional security. Global config: nsr process-failures switchover tcp path-mtu-discovery tcp selective-ack logging console disable snmp-server ifmib stats cache ssh server logging no telnet vrf $vrf-name ipv4 server ssh client source-interface $$loopback0 logging events link-status software-interfaces Admin config: upgrade fpd all loc all fpd auto-upgrade Interface config: interface [interface name] ipv4 unreachable disable ipv6 unreachable disable dampening 1 xxx yyy 1 OSPF config: router ospf…

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For IOS, the equivalent command of “write erase” to IOS-XR is the command “commit replace” RP/0/RSP0/CPU0:ASR9K(config)#commit replace ? best-effort   Commit the configuration changes via best-effort operation comment       Assign a comment to this commit confirmed     Rollback this commit unless there is a confirming commit force         Override the memory checks label         Assign a label to this commit save-running  Save running configuration to a file show-error    Displays commit failures immediately <cr>     …

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How to upgrade Field Programmable Device (FPD) on Cisco IOS XRAs per Cisco official documentation, the definition of FPD as follows: An FPD refers to any programmable hardware device on a router, which includes a Field Programmable Gate Array (FPGA) and Read Only Memory Monitor (ROMMON). Cisco IOS® XR routers use a number of FPDs that are crucial for the function of route processors, line cards, shared port adapters (SPAs), SPA Interface Processors (SIPs), and fan trays.1. Use the command…

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These are the steps in upgrading Cisco IOS-XR from 5.x.x to 6.x.x1. Download from Cisco website the necessary files for the upgrade, usually images are in package installation envelope (.pie) format. One way of transferring  files to the router is via USB port, thus copy these files in your USB thumb drive and insert in USB port in your active RSP linecard.2. Copy files from usb to harddisk. dir usb: RP/0/RSP0/CPU0:CISCO-A9K#dir usb: Directory of usb: 131648      -rw-  23790534 …

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Installation Files needed for Cisco IOS-XR The required files can only be downloaded via Cisco official website and needs an authorized account. Just go to ‘Software Download’ and search for the product name. Select for the software types, sample as follows: IOS XR Service Packs IOS XR Software (this is where you can download main packages) IOS XR Software Maintenance Upgrades (SMU) IOS XR Software Maintenance Upgrades (SMU) Bundles The files needed depend on user or organization requirements, services offered…

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Cisco IOS-XR Minimum System Requirements for Upgrade For upgrading IOS-XR devices like ASR9000 routers, e.g. from 5.x to 6.x , the minimum memory requirements for ver. 6.2.3 are: minimum 2 GB compact flash on RSPs or Route Switch Processors minimum 6 GB memory on the RSP-440 and RP (ASR99xx) minimum 4 GB memory on LCs or Line Cards Command that can be used to find the physical memory of each modules: show watchdog memory-state location all | include “node|Physical Memory:”…

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These are the some commands being used when performing network change or maintenance, depending on the features or services being run in the network. Typically, this is very useful in verification, troubleshooting and comparison between before and after the change. terminal exec prompt timestamp terminal length 0 show version show run show filesystem location 0/rsp0/cpu0 show filesystem location 0/rsp1/cpu0 show ipv4 interface brief show ipv6 interface brief show route ipv4 summary show route ipv6 summary show route vrf all ipv4…

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Checking TX / RX optical power for Cisco IOS, IOS-XR, NX-OSFor checking transmission links, it is good to know how to find out the optical power for troubleshooting and making sure the desired or optimal range is meet. Here are the sample commands for checking the TX/RX optical power. IOS / IOS-XE If want to check TX & RX power for IOS based devices such as ASR1K ,e.g. interface GigabitEthernet 0/2/2,here’s how to do it:   IOS-router#show hw-module subslot x/x…

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