At a friend's birthday party dinner this evening in a very fancy Italian restaurant as we all finished dinner and everyone somehow felt it was appropriate to whip out that iPhone and start texting the buddies at the other long end of the table, the guy beside me suggested let's play Ask Siri!
I don't have an iPhone, I don't even own a cell phone really. I'm very curious who is Suri (I didn't even know how to spell it). The "Industry Canada RF Bandwidth Allocation Committee member" rolls her eyes and says, you folks are wasting bandwidth! I suppose this is true, asking age old questions like why did the chicken cross the road, what is the meaning of life, who's your daddy, and How big is the Pacific Ocean? (that's a good one) Siri gives the answers in Liters with extra information about the comparative volume, 51% of the all the earth's oceans. I'm hooked. I ask, What is Pippa Middleton wearing? Siri displays button to perform a website for that. I'm giggling too much at the idea of asking a computer for answers. I get one of the guyz to ask, what are you wearing Siri? But I miss the answer because it's just too funny.
We're at a birthday party so buddy asks, Siri would you sing happy birthday to my friend please?
Siri answers, Daisy, daisy, give me your answer do.
It wasn't quite the answer I was searching for. People keep texting each other or playing Angry Birds, but I desire an explanation! The Cisco guy at the end of the table explains that it is a cultural reference to the IBM computer that became the first computer to sing Daisy Bell.
In the late 1950's a computer sung a song for the first time. Here is a nice clip from YouTube.
Daisy, daisy, give me your answer do.
I'm half crazy all for the love of you.
It won't be a stylish marriage -
I can't afford a carriage,
But you'd look sweet on the seat
Of a bicycle built for two.
This is quite a cute response. I guess it's an AI joke that's preprogrammed in, but it's still very cute. Well here are some other questions to ask Siri though personally I think people should really talk to their friends at a party and not play with their phones too much. Tweet tweet.
Sunday, March 4, 2012
Saturday, March 3, 2012
Would you like a slice of Raspberry Pi?
10,000 units sold out in minutes, a $35 programmable GNU/ Linux mini computer the size of credit card. I gotta get one of those on the next batch they bake. It was created in Toronto and manufactured in the UK!
It's so sweet that the inventors initially created this device to be accessible in cost and available one per person with the intention that kids could learn programming.
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It's so sweet that the inventors initially created this device to be accessible in cost and available one per person with the intention that kids could learn programming.
Thursday, March 1, 2012
Mobile IPv6 for earth
Studying for the CCNA Exam and the next topic is ipv6. I remember my teacher explaining that the last ipv4 address was given out in November 2011, and the number one reason was the proliferation of smart phones requiring an IP address. Did some reading on cell phones in general, curious on what's new because I don't even own one myself, and my brother keeps bugging me that I'm missing out (What, on Angry Birds?) and they mentioned about mobile IP and I put the two ideas together.... well they must be using IP v6!
Mobility driving the requirement to maintain the same IP address while moving seamlessly across different networks. That's pretty cool. Read all about Mobile IP.
So do all the addresses really start with 2 (for planet earth?). The prof also had a few other wacky ideas too, like he could write a book about IPv6 in less than page, and that to make millions in IT just sign up to be the IPv6 networking guy. It would be easier job ever. Really? So I guess this is my book on IPv6: (Be careful with the use of colons, they mean something!)
The IPv6 address is formed from 32 bits of hex.
The global unicast begins with 2000
The Link Local Address refers to the physical link
- not for forwarding datagrams
- for neighbor discovery and route discovery
- begins with FE80 <internal mac address> or FFEE
The Loopback address is ::1 which means all preceding zeros.
Unspecified address
- a host looking for his own address
0:0:0:0:0:0:0:0 or ::
Stateless Autoconfiguration
prefix + interface ID
Stateless DHCP
HOW TO Enable IPv6 on a router
usage: ipv6 unicast routing
usage: ipv6 address 2001:db8:c18:1:: 64
(the first part was the global address, no need to write sequential or preceding zeros, the 64 means eui-64)
* Specify the 64 bit prefix by using eui-64 if you want the router to derive interface ID portion from mac addres
* You can automatically get the link-local address FE80:
show ipv6 int ethernet 0
RIP based on RIPv2
* uses the multicast group FF02::9
QUIZ
Do you want to be IPv6 Certified by Hurricane Internet Services? Here is a quick link to a neat service. I think they are a web hosting service.
Mobility driving the requirement to maintain the same IP address while moving seamlessly across different networks. That's pretty cool. Read all about Mobile IP.
So do all the addresses really start with 2 (for planet earth?). The prof also had a few other wacky ideas too, like he could write a book about IPv6 in less than page, and that to make millions in IT just sign up to be the IPv6 networking guy. It would be easier job ever. Really? So I guess this is my book on IPv6: (Be careful with the use of colons, they mean something!)
The IPv6 address is formed from 32 bits of hex.
The global unicast begins with 2000
The Link Local Address refers to the physical link
- not for forwarding datagrams
- for neighbor discovery and route discovery
- begins with FE80 <internal mac address> or FFEE
The Loopback address is ::1 which means all preceding zeros.
Unspecified address
- a host looking for his own address
0:0:0:0:0:0:0:0 or ::
Stateless Autoconfiguration
prefix + interface ID
Stateless DHCP
HOW TO Enable IPv6 on a router
usage: ipv6 unicast routing
usage: ipv6 address 2001:db8:c18:1:: 64
(the first part was the global address, no need to write sequential or preceding zeros, the 64 means eui-64)
* Specify the 64 bit prefix by using eui-64 if you want the router to derive interface ID portion from mac addres
* You can automatically get the link-local address FE80:
show ipv6 int ethernet 0
RIP based on RIPv2
* uses the multicast group FF02::9
QUIZ
Do you want to be IPv6 Certified by Hurricane Internet Services? Here is a quick link to a neat service. I think they are a web hosting service.
Monday, February 27, 2012
Cisco Port Security
Use port security to manage the ingress of traffic from dynamically learned and static MAC address. When a secure MAC address is assigned to a secure port, the port will not forward traffic from any other MAC address outside the defined MAC Address.
There is a security violation if one of these infractions occur
1) When access is attempted by a MAC addresses that is different from any of the identified secure MAC addresses, port security applies the configured violation action or mode.
There is a security violation if one of these infractions occur
1) When access is attempted by a MAC addresses that is different from any of the identified secure MAC addresses, port security applies the configured violation action or mode.
2) If traffic with a secure MAC address that is configured or learned on one secure port attempts to access another secure port in the same VLAN, port security applies the configured violation action or mode. It is a move violation!
Possible actions are:
switchport port-security violation {protect | restrict | shutdown}
protect—Drops packets with unknown source addresses until you remove a sufficient number of secure MAC addresses to drop below the maximum value.
restrict— the same, but causes the SecurityViolation counter to increment.
shutdown—Puts the interface into the error-disabled state immediately and sends an SNMP trap notification.
To bring a secure port out of the error-disabled state, in global configuration mode
usage: errdisable recovery cause violation_mode command
or manually reenable it usage: shutdown and no shut down interface configuration commands
To prevent overtaxing the CPU, use the port security command with rate limiting
usage: errdisable recovery cause violation_mode command
or manually reenable it usage: shutdown and no shut down interface configuration commands
To prevent overtaxing the CPU, use the port security command with rate limiting
Methods of MAC address configuration
Static
How to statically configure all secure MAC addresses?
Dynamic
Dynamiclly configure secure MAC addresses?
1) You can allow the port to dynamically configure secure MAC addresses with the MAC addresses of connected devices.
2) You can statically configure a number of addresses and allow the rest to be dynamically configured by sticky!
Sticky MAC addresses
These can be learned dynamically. Port security with sticky MAC addresses retains dynamically learned MAC addresses during a link-down condition.
Remember to write memory (wr is the shortcut) or copy running-config startup-config command, then port security with sticky MAC addresses saves dynamically learned MAC addresses in the startup-config file. Theport does not have to learn addresses from ingress traffic after bootup or a restart.
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