Wassim

Just like you wear a watch to have time, network devices have a time protocol called NTP that does just that. The following are my study notes on the subject. There are two types of clocks: hardware clock and software clock. The hardware clock has its own battery. When router shuts down, hardware calendar still works. When we reboot router, the software clock synchronizes with hardware clock, even if we already set the software clock. Once the software clock is user-defined, we can synchronize the hardware clock with it, with “clock update-calendar”. with “show clock” and “show clock detail”, if an asterisk is displayed then the time server is not authoritative which means that it is not reliable. The protocol has a notion of stata . Each time server has a stratum: Server with stratum 0 has more precise time than server with stratum 1, etc. Server with stratum 1 feeds server with stratum 2, which feeds server with stratum 3, etc. NTP synchronises sof...

We learn in this post how to configure route redistribution between OSPF, EIGRP, BGP and static routes. The first section depicts OSPF route redistribution into EIGRP. The second section gives an example of redistributing static routes into EIGRP. And lastly we see an example of redistributing BGP into OSPF. Injecting OSPF prefixes into EIGRP – On the ASBR, and after redistribution, there’s a change in EIGRP topology table. But no changes happen in the routing table: before redistribution: after redistribution: The change happens on the other routers, i.e. DSW1 and DSW2. Redistribute ospf match internal Before this command, here’s DSW1 RIB: Then: The 10.1.1.8 prefix is a subnet that’s internal to OSPF, i.e. it was not redistributed into OSPF before arriving to R4. The 0.0.0.0/0 is also an OSPF Internal route (the default route that’s injected by R3 into the totally stub NSSA) . So it is redistributed into EIGRP too. “redistribute ospf ..”, wit...

this will be my lab for TSHOOT practice. It’s taken from here

Sometimes it seems that things don’t go as expected. Sometimes I think I made mistakes or I did bad calculations. But what if I was asking myself wrong questions? What if I say to myself : – what do I really want, if I knew it was achievable? – what can I do, to enjoy my time more? – what are the things I’m grateful to Allah for right now? – How can I improve my lifestyle, my health and my relationships? – what if I was in the right relationship with the right girl, and I wasn’t noticing it? – what if all this is part of my experience? – what if all the things around me happen for a reason? – what if I could achieve anything I want in life and I wasn’t aware of my potential? – what if I had the potential to surpass all the people I knew in my life? What if?

this demonstrates that IP CEF is not enabled, until SVIs are created: Once SVI is created, CEF tables are created too, and stay there even if we delete the vlan and the SVI: Now we set back vlan 101 and its SVI. We display the FIB table: We do a ping to the attached host (in the vlan). A new entry is added to FIB: We create SVI 103. FIB is updated. Then we ping from host1 to SVI 103: Now let’s show the adjacency table AT:

In this post, we will learn the following things about qos: why it is important to have a QoS policy, the traffic profile requirements for data, voice and video, how to define and implement a QoS policy. What is QoS, really? QoS can be defined as a way to ensure a quality of service of a transport system and to control its performance, especially in congestion time. It encompasses the following techniques: Classification Marking Congestion Management Congestion Avoidance Policing and Shaping Link Efficiency QoS helps network engineers reduce or eliminate the famous traffic performance enemies: delay, jitter and packet loss. But in no case can QoS substitute a bandwidth upgrade. For example, with QoS, we can select which packets to be dropped and which to be queued, thus even if packets are to be dropped, they won’t affect the most important traffics we have. Traffic profiles You might have learned in the past that there are data applications and multimedia applications. Here, we will t...