Posts

First IPv6 Home Project failed

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For the past few days, I've been trying to implement a dual-stack network for my home VLAN (non-IoT), but today it fails due to no supported feature set on some devices in my network. I want to describe the details so that you too can learn from my mistakes or guide me to do better. My home network is designed like this: If you remember, I have written an article " Does NAT66 or NPTv6 need it? " These are similar requirements. My ISP modem and Dream Machines, both are designed to obtain IPv6 using the Prefix Delegation or static assignments. The ISP modem is getting PD subnet, but it is failing to supply to the Dream machine. Now, I have a single option for assigning IPv6 as Static on the Dream Machine. And I have assigned the Site Local Subnet in the LAN and configured NAT with ipv6table. Used nonstandard option as ip6tables -t nat -A POSTROUTING -o eth4 -j MASQUERADE. There is no direct option to configure NATv6.NAT66, NAT64 etc. What was the failure with this scenario:...

Does NAT66 or NPTv6 need it?

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Does NAT66 or NPTv6 need it? Let's understand the NAT requirements with an Ipv6 address. Have you ever heard that we don't require NATing with IPv6? Is it true?  My answer will be yes if you are a CCNA student, otherwise, it is only a half-truth. How? Let's try to understand with a few examples: 1. In Theoretical or book statements, IPv6 does not require any NATing because we have enough IPv6 Addresses. Your ISP might supply a/48 prefixes, so you have more than the required networks or prefixes for your office/home. So mostly you will not have to translate from private to public or vice versa. But is it a 100% true statement? I think no and practical is also approved no. Let's check other points.  2. What if your ISP modem does not respond to the Client's RA messages? If you still need Ipv6 Enabled network, then you mostly prefer to use NPTv6.  3. In the future you might change your ISP and you don't want to be stuck in a face to reconfigure the complete network...

One Line Learning Posts - 3 BGP

 Today we will cover some confusing options of the BGP 1). Route Dampening is only working for eBGP routes. It will not trigger on iBGP route. This technique is applied when receiving updates from external peers only (EBGP). Applying this technique to IBGP learned routes or to advertisement to IBGP or EBGP peers after making a route selection can result in routing loops. 2).  Peer Group : Since IOS version 12 manual peer group configuration is no longer necessary to achieve this optimization. IOS is capable of recognizing neighbors with the same outbound policy. These are then grouped together automatically. This is a feature called Dynamic Update Peer Groups. You can check the Dynamic groups using the command "show IP bgp update-grou p" command.  Changing a policy in out direction to a neighbor will also change the update group in the backend.  3). Simplifying Route Reflector rule : Books say there are three rules. But as per my complete understanding of this...

BGP Slow Peer Detection

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 What is Slow peer detection? We have a group of routers with the same outgoing route-map (outbound policy), which means the router will place all neighbors in the same group because the router wants to save resources to perform the same task multiple times for example: sending route updates.  The router will select a "Leader Router or Neighbor" and perform update or other algorithm tasks and will also replicate to all other routers in the same group.  What if any of one router is too slow due to hardware or software issues? This slow router is called Slow Peer. Slow peers affect the BGP convergence of the entire update group. If one BGP peer is slow, it causes the entire update group to slow down. The result is that the other update group members will have slower convergence as well. For this reason, the issue should be resolved. You can identify the slow peer and move it out of the update group. In order to complete this task, you can change the outbound policy for...

One Line Learning Posts - 3 MPLS VPLS

  Kompella method, Pseudowire is signaling via BGP which is one of the methods (Juniper) Martina method , pseudowire is signaling via LDP which is a second method (Cisco). This is the default method on Cisco Boxes. It does not support Autodiscover.  When multihoming a VPLS site (potentially in different autonomous systems [ASs]), the PE routers connected to the same site can either be configured with the same VPLS edge (VE) device identifier or with different VE device identifiers. If you are using different VE device identifiers, you must run the Spanning Tree Protocol (STP) on the CE device, and possibly on the PE routers, to construct a loop-free VPLS topology. Two VPLS NLRIs are considered equivalent from a path selection perspective if the following are the same: Route distinguisher VE device identifier VE block offset (the default VE range of 10 is applied) If two PE routers are assigned the same VE device identifier in a given VPLS, they must also advertise the same ...

One Line Learning Posts - 2 BGP

 Today's topic is BGP: 1).  For Incoming traffic from the other AS to Local AS, BGP MED , AS-PATH Prepending , and Community Attributes can be used.  2.  BMP (BGP Monitoring Protocol) is an automated way of collecting BGP data from routers.  3).  BMP offers following Advantages as: Configure devices to function as BMP servers, and set up parameters on the servers, that are required for monitoring of the BGP neighbors. Establish connectivity of the BMP servers with BGP neighbors for monitoring. Generate statistics report from monitoring the BGP neighbors. Perform appropriate error handling on the BGP neighbors. Graceful scale up and degradation to the point of closing connectivity between the BMP servers and BGP neighbors. Read More about BMP :    

One Line Learning Posts - 1 MPLS

 A unique line posts are for your learning and notes. Will write down this type of post every day.  You can copy and paste it into your notes.  1). If you don't have Router Reflector in the MPLS networking and use full mesh connectivity, then you don't require Different RDs for installing two or more routes in the routing table.  2). Route Target (RT) is an extended community attribute used to import and exports VPN prefixes to and from VRFs.