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cisco

  • 2021-04-19
  • 2021-04-19
  • 0件

List and how ” | ” pipeline commands for Cisco devices

Do you know the “| pipeline”, a command technique that should be used by those who manage and set up Cisco devices?? It is a basic skill among network engineers who use Cisco devices, but many front-end engineers who do not usually touch the equipment do not know. You can use this pipeline to display only some of the lengthy commands that are output in the CLI. I often use the show run command, but most of the output is unnecessary, isn’t it? About | ” command Read “|” ← pipeline First of all, you don’t know how to read this symbol. smile It is called a “pipe” or “pipeline”. I often don’t know how to call it and can’t tell my customers and partners by mouth. How to 「|」 Type the command that is provided after < a0>, and then type any string.</a0> This “|” Searches for strings in the output of commands entered before < a0>, and changes the output. </a0> (Since it is difficult to understand, the following is an example.) ) For example, in the example above, you can use the “show run” |” I’m using . 「|」 is followed by “inc” (include) and the string […]

  • 2021-04-05
  • 2021-04-05
  • 0件

Be careful with meraki MR’s L3 firewall settings

Meraki, a cloud-managed network device that is one of the Cisco products, has attracted a lot of attention in recent years! It is also very easy to set up, manage, and become a very convenient and popular product in remote work environments. In addition, it is very speedy at the time of introduction, and it can be used simply by connecting Meraki to a port that is connected to the Internet. It is a very favorite product among me! Therefore, I will introduce the MR series “Default setting of firewall function” that I met many times in various environments in the author. About meraki MR series firewalls About features The Meraki MR series is an access point, but a firewall function is implemented. There is a “firewall”, but it is not a function like UTM, but “access list (ACL)” of layer 3 and layer 7. (*Adult content filtering is possible in NAT mode.) ) Layer 3-level ACLs allow you to specify transport protocols (UDP, TCP, ICMP), destination IP addresses (segments), and destination port numbers, allowing/blocking radio client traffic as it crosses mr uplinks. Note) Cisco devices basically have ALL Deny set on the last line, while Meraki MR has ALL […]

  • 2021-04-04
  • 2021-04-04
  • 0件

Operation by ACL “Packet generated by the router itself”

Cisco qualified CCNA and CCNP frequently have access list (ACL) issues. Or y, it is always asked. Among them, there is content that the examinee often mistakes, and there is a content that “can not be solved undying if you do not know it”. The content is “Packets generated by the router itself are not subject to the access list”. Let’s test if the packet is actually uncontrolled. Test configuration Configuration/Settings Set the following access list to Cisco 891fj and Ping another router with ip address 192.168.55.1. * By the way, it is necessary to set protocol settings and destinations, so use extended ACLs. The access list 100 specifies a protocol ICMP, and the source is Any (all), and the destination is set to 192.168.55.1. Then set the access list 100 to the out direction (egress) of GigabitEhternet8 on the orange router. This should control ICMP packets from the orange router to 192.168.55.1. Router#show run int gi8 interface GigabitEthernet8 ip address 192.168.55.80 255.255.255.0 ip access-group 100 out duplex auto speed auto Router#show access-lists | sec 100 Extended IP access list 100    10 deny icmp any host 192.168.55.1 Since “implicit Deni ALL” is set to the last line, all resulting […]

  • 2021-03-29
  • 2021-04-04
  • 0件

[350-401]Cisco EtherChannel PAgP Mode Combination

Question Which of the following combinations of PAgP modes prevents etherChannel from forming? auto/desirable desirable/desirable desiravle/auto auto/auto See answers (4) Commentary Combination of EtherChannel (PAgP) operating modes Cisco’s proprietary EtherChannel negotiation mechanism PAgP has two modes to set up the interface. Desirable Enable PAgP unconditionally. Start sending negotiation messages to other ports. Auto Enable PAgP only when a PAgP device is detected. In other words, it waits for an on-the-other request and responds to a request for PAgP negotiation. This reduces the transmission of PAgP packets. Auto and Auto do not start negotiating PAgP from the above mode. A combination of Desirable/Desirable and Desirable/Auto is required to use PAgP. Therefore, the combination that prevents formation is ④.

  • 2021-03-25
  • 2021-04-04
  • 0件

[350-401] Difference between FIB and RIB part.1

Question Which of the following is correct about the difference between RIB and FIB? FIB creates data based on RIB. RIB maintains the mirror image of FIB. The RIB is used to make a switch decision based on the IP source prefix. All IP routing information is stored in the FIB.   See Answer ①   Commentary FIB(Forwarding Information Base) FIB is a table that stores transfer information generated when the switching mechanism CEF (Cisco Express Forwarding) is enabled on the device. The FIB contains prefixes from IP routing tables or global RIBs that are structured in a way that is optimized for forwarding. When a routing or topology change occurs in the network, the IP routing table is updated and these changes are reflected in his FIB. The FIB holds the next hop address information based on the information in the IP routing table. RIB(Routing Information Base) A central repository for routes containing L3 reachability information and source IP addresses or prefixes. RIB is also known as the routing table. <reference>https://www.cisco.com/c/ja_jp/td/docs/cian/ios/ios15-1s/cg/013/isw-15-1s-cg/cef-overview.html#16041

  • 2021-03-05
  • 2021-04-04
  • 0件

How to check the feature list for each product / OS of Cisco Wireless

There are two types of OS such as Aire OS and IOS XE for Wireless products of Cisco, and there are various management forms such as Cisco 〇〇 series and Catalyst series in WLC (Wireless Lan Controller). There are Autonomous, Lightweight, CME, EWC, etc. in AP mode, which are very complicated to introduce. Of course, there will be a “difference” in the functions that can be used depending on the AP mode and OS. To be honest, I want you to unify. I think this is to enable flexible introduction / proposal in various environments. You can easily check the list of functions by these modes and OS in “Feature Matrix” published by Cisco. Feature Matrix for Access Point First, let’s take a look at the official Cisco website <Feature Matrix for Wave 2 and 802.11ax (Wi-Fi 6) Access Points>. How to See From the “Table of Contents”, first click on the OS and mode you plan to install / use to scroll the page to the list of each function. For example, if you want to use it in FlexConnect mode with Lightweight, see “FlexConnect Feature Matrix (Aire OS)”. The leftmost column, “Features,” lists common wireless features and Cisco […]