Wassim

in TSHOOT topology, we have a DHCP client (client1) on vlan 10. Broadcast traffic from the client to the DHCP server should be allowed to pass through DSW1 and DSW2. So where to put “ip helper-address”? it depends on which switch will take the HSRP Active state. First, check the spanning-tree instance on vlan 10. Then, see which is the HSRP Active gateway. If for example DSW1 is the Active HSRP, then “ip helper-address AddrA” should be put under “interface vlan 10” of DSW1. Beware that AddrA is the ip address of R4 interface. And this value is: – 10.1.4.6, if DSW1 is HSRP Active gateway, – 10.1.4.9, if DSW2 is HSRP Active gateway. This took me an hour or so to figure out, maybe because I’m a little tired :-)

Two days are left before I sit for my TSHOOT exam. I feel confident about it since I have a first taste of it: I read feedback given by test takers that it was a nice experience. I practiced the official Cisco TSHOOT topology on GNS3 with different protocols. I ought to be ready for both scenarios: – If I succeed, then I know that all my limiting beliefs about CCNP were wrong. I would know that I was prisoner of my false beliefs. – If I fail,  I should remind myself about all the courageous people in the world who spent a lot of money and time in the pursuit of their certs.   Either way, I’ll learn something, and that’s my own choice. I made my choice to enhance my career, no matter what the sacrifices are. “Courage is resistance to fear, mastery of fear – not absence of fear” – Mark Twain

Breathing is taken for granted and most people think it comes naturally and from the chest. In fact, I myself thought that the lungs push the chest upwards, which explains the chest movement up and down. But as hard as we try to breathe the conventional way we tend to feel “tired” from breathing at the end of a work day especially if you are like me a network engineer or a person who is sitting for a long time in a desk/office. And you probably experience the following symptoms: sense of culminated stress sense of fatigue/drowsiness at the end of the day loss of appetite. I tried one day and I practiced deep breathing the whole day. I mean, inhale slowly with my nose until my lungs are full and exhale totally through my mouth until my lungs are “empty” and my stomach is stressed. Does it have benefits? I totally agree: – I felt more focused on what is most important to me at one time, – I could work steadily without feeling tired, – I did not fe...

dot1x – dot1x can work with DHCP address assignment – only EAPOL is allowed before a port is authorized – Vlan Assignment (by a RADIUS server) depends on the result of dot1x authentication – RADIUS server- the dot1x authentication server- is the one which verifies the identity of the client connected to a dot1x port AAA – there are named method lists (simply method lists) – once AAA is enabled, the default method list is applied to console, VTY access, enable mode…

show | redirect to display cisco.txt file on console: show | tee The output is displayed then redirected to file cisco.int.txt: show cpu processes cpu history : the following 3 screenshots. show processes config replace – I changed the hostname on ASW1. The change is seen on the running-conf and not on the startup-conf. – we want to rollback changes, i.e. restore the original hostname by restoring the startup-config. The latter resides on the NVRAM: we perform the rollback with “list” option, to see the changes. We see that hostname is back to ASW1:

I didn’t know that Cisco incorporated IPv6 and RIPng into its CCNA courses until now! that demonstrates that Cisco is keeping the value of its certs high in the market. I’m proud to be studying networking in general, and Cisco in particular. Showing RIPng configuration information show ipv6 protocols We can see which interfaces are participating in RIPng show ipv6 rip RIP_ZONE displays various information about the RIP_ZONE process Debugging RIPng debug ipv6 rip – see that link local addresses are used in multicasting – destination address is multicast FF02::9 ———– In my home TSHOOT lab, R4 has only fa0/0 in RIPng. – The split horizon rule is a loop avoidance technique that prevents a route from being advertised out the interface through which it was learned. Route redistribution into RIPng We’ll configure it on router R4, because here it is the ASBR between OSPFv3 and RIPng. We chose metric 10 because Seed metrics shoul...

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...