Understanding Technology One at a Time!!!

Hello all in my certification rush got through some gift vouchers from my friends and went on to attempt my first ever 70-290 just to try my luck .. went through the study guide and poof went through exam .

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Hello all two good news to start wtih

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Hello guys , i have made a video on deploying and implementing syslog server in gns3 environment . A syslog server logs all messages from routers in gns3 and records them .

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Dont know why my mind has been in an unpredictable state .. nothing settling down .. wanted to for jncia-ex as per my last posting .. dint get chance as i was attracted by cisco v4 written beta . done with mpls and ipv6 which were troubling me in two days .. now after that a thought came into my mind to prepare for jncia-ex switching which was obviously easy when compared with other tracks atleast .. quickly went through the study guide ..

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Hello myself and another friend of mine are going for our rs studies and were on gtalk last night discussing some multicasting and general prep stuff . I suddenly got an idea on remote desktop and heard about team viewer few months ago. Quickly went to their website and downloaded the stuff .

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Hello everyone as you know if i come across any exciting stuff i share with most of you . I happened to get narbik ‘demo’ of his cod which was roughly around 10min on ospf filtering techniques and the entire cod was awesome … In ten minutes he covered most of the info with minute details . The demo vod should be up with in a day or two . can’t wait to get hands on that one as iam going for rs v4 which includes troubleshooting.

for more info you can always visit his site @

http://www.net-workbooks.com/index.html

will update you if i happen to find any interesting stuff again ..

guday and take care

Rakesh

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A sudden catastrophic change of plans has taken place in past 12 hours . i was happy that i got all of the juniper voucher and was about to take jncia-er exam this week until i went to cisco’s website and found that ccie written v4 is now in beta phase and offered for as low as 50$ . Well who wont take that price (atleast students like me ) to go out and take a dreadful exam which was 350$ and that too completely changed with mpls and troubleshooting introduced.

so , cant help for another month . i have been studying stuff seriously .. done with ipv6 stuff and will let you know if possible . iam excited about this beta exam even though i know it would be insanely tough to pass i still give the exam hell before it declares me as fail hehe

Thank you and sorry for change of plans

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Topology :

-> minimum of requirement is that there must be multiple routers which are capable of running vrrp in a lan segment.

-> if there are two wan circuits and if there is any routing policy in place which uses only one wan link out of two vrrp should be tuned in such way.

Master or Backup:

->Beefy configuration router is obviously preferred over the non-beefy one as master

-> Assignment of VIP address is one among the important aspects.

Load Balancing:

-> load balancing can be a tricky part . well not let us agree not that hard. assign two routers as masters. assign half routers with one vip address and others with other vip address. Load balancing will be done swiftly.

Preemption:

-> By default preemption is enabled by default. Disable preemption to eliminate unneeded mastership changes during failure and recovery scenarios if you have both routers as masters.

Security:

-> option exists for security vrrp exchanges.

first option : No Authentication

second option : simple text password

third option : most secure : HMAC-MD5-96 (md5)

Avoid Wan link Failure:

-> Either have complete Redundancy

-> Other implement Interface Tracking

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-> 4 STATES

* INITIALIZE

* MASTER

* BACKUP

* TRANSITION

-> Initialize:

-> All routers begin in initializing state which essentially announces each vrrp participating routers capability , priority and other parameters

-> No forwarding of packets will be done in this stage as there is no master vrrp router to do the forward.

->Master/Backup:

-> A master router assumes the responsibility to forward packets and answer arp requests to the VIP address from the hosts

-> Master sends periodic announcements which indicates master router’s state and priority.If these announcements are not received for a specific period of time the back up router takes the role of the master router.

-> Routers in the backup state observe masters presence and be ready to take the role if master is down.

->Transition:

-> In the event of mastership change, the backup router might fora very brief moment , be in what is known as the transition state. This state is simply a transitional step in which a router changes from the backup state to the master state where in no forwarding occurs for LAN.

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-> Vrrp version 2 uses common advertisement packet (Buzz word) to communicate with other vrrp routers.

-> vrrp uses multicast address of 224.0.0.18 and has TTL of 255.

-> Default interval can be changed if needed . default being 1 and range being 1-255 subseconds can also be configured from 100-999 milliseconds which must be supported by all vrrp routers.

-> The above can be done with “fast-interval” option

-> Fields which should match in a vrrp packet for all vrrp routers

-> VRID
-> Authentication Parameters

if not then packets are discarded

-> Vrrp router uses Virtual mac address as its mac address when it sends a packet.
format may be some thing like this 00-00-5E-00-01-VRID

Determining Master:

-> Higher priority wins in a vrrp election process. The default being 100 and range being 1-255

-> A router can become a Master Router only when it has VIP address and in that case the priority must be set to 255. preemption is supported by default . If master happens to fail the other router which has higher priority will take over and if by chance master returns the other router will be down and this will take over the master role.

-> We can administratively disable preemption where vrrp routers do not own VIP address.

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