RE: CCIE Written Question [7:44578]
Pls. see below : 0200.1078.0400 Write in binary : 0200 10780400 0010 0001 0111 1000 0100 After that exchange as under 0010 0001 1000 0111 0100 And then 0100 1000 0001 1110 0010 Conver them to HEX 4000 081E2000 Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=45125t=44578 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: CCIE Written Question [7:44578]
Very good. just on time. I am going to take my CCIE written this Friday. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=44663t=44578 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: CCIE Written Question [7:44578]
The problem of canonical and non-canonical MAC addresses exists because Token Ring devices start reading each bit of a byte at the most significant bit, while Ethernet devices start reading each bit of a byte at the least significant bit. The 0's and 1's are exactly the same on the Token Ring wire as they are on the Ethernet wire. It is how the Network Interface Cards (NIC) and device drivers read the 0's and 1's that is different. For example, an Ethernet host would see 0100 when reading an unconverted byte sent from a Token Ring host as 0010. Since we usually look at MAC addresses in Hexadecimal, let's review how to convert the numbers for our purposes. Take a look at the table below. It provides the converted hex digits, and binary examples to show how the numbers were derived: 0=0 ( - ) 8=1 (1000 - 0001) 1=8 (0001 - 1000) 9=9 (1001 - 1001) 2=4 (0010 - 0100) A=5 (1010 - 0101) 3=C (0011 - 1100) B=D (1011 - 1101) 4=2 (0100 - 0010) C=3 (1100 - 0011) 5=A (0101 - 1010) D=B (1101 - 1011) 6=6 (0110 - 0110) E=7 (1110 - 0111) 7=E (0111 - 1110) F=F ( - ) When converting from canonical and non-canonical, or the other way around, take the address in one byte (two hexadecimal digits), convert the digits based on this chart or by actually reversing the bits. Once the individual digits are converted, swap them. For example, A7 would become E5, and E5 would become A7. There are several examples in the questions at the end of this chapter. I hope that helps... --- Dennis - Original Message - From: Hunt Lee To: Sent: Monday, May 20, 2002 5:11 PM Subject: CCIE Written Question [7:44578] I was just wondering if anybody knows a way to translate Ethernet MAC (Cananical) to Token MAC (non-Cananical) vice versa?? I know how to do the simple ones: e.g. 1078.xsxx. HexDec SwapDecHex 10 = 16= 0001 = 1000 = 8 = 08 Or any other ones like DecHex 101 202 303 404 505 606 707 808 909 10 0A 11 0B 12 0C 13 0D 14 0E 15 0F 16 10 17 11 18 12 19 13 20 14 21 15 22 16 23 17 24 18 25 19 But I don't know how to do it if they give me a large one e.g. Hex of 78, or AC etc?? Thanks. Best Regards, Hunt Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=44581t=44578 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: CCIE Written Question [7:44578]
Hello, I just want to add my own to what Dennis has said (actually I have learned it from his book too - Thanks Dennis) How can you easily memorize this you may be wondering... 0=0 ( - ) 8=1 (1000 - 0001) 1=8 (0001 - 1000) 9=9 (1001 - 1001) 2=4 (0010 - 0100) A=5 (1010 - 0101) 3=C (0011 - 1100) B=D (1011 - 1101) 4=2 (0100 - 0010) C=3 (1100 - 0011) 5=A (0101 - 1010) D=B (1101 - 1011) 6=6 (0110 - 0110) E=7 (1110 - 0111) 7=E (0111 - 1110) F=F ( - ) Like this: 3 Cats 5 Apples 7 Elefants and DeciBel. These stand for: 3=C (and C=3 of course) 5=A 7=E D=B The rest is really easy to remember because they are very easy to project in your head in binary. 0=0 F=F 6=6 9=9 F=F 1=8 2=4 Good Luck, Peter Peter Ivo Racz Hunt Lee wrote: I was just wondering if anybody knows a way to translate Ethernet MAC (Cananical) to Token MAC (non-Cananical) vice versa?? I know how to do the simple ones: e.g. 1078.xsxx. HexDec SwapDecHex 10 = 16= 0001 = 1000 = 8 = 08 Or any other ones like DecHex 101 202 303 404 505 606 707 808 909 10 0A 11 0B 12 0C 13 0D 14 0E 15 0F 16 10 17 11 18 12 19 13 20 14 21 15 22 16 23 17 24 18 25 19 But I don't know how to do it if they give me a large one e.g. Hex of 78, or AC etc?? Thanks. Best Regards, Hunt . Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=44586t=44578 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: CCIE Written Question [7:44578]
Hunt, I hope you get something good from my post. having said that.. I'm letting loose flames or not.. Okay. maybe this time I've had a too few many beers. but COME ON PEOPLE!!! What's the problem with bitswapping?!?!?!? There are 16 possible conversions from binary to hex (assuming the standard 4-bit binary to single digit Hex conversion): 0 0001 1 0010 2 0011 3 0100 4 0101 5 0110 6 0111 7 1000 8 1001 9 1010 A 1011 B 1100 C 1101 D 1110 E F When you bitswap, follow this process: 1) Swap each hex digit in the byte: 1D now becomes D1. 1D C2 now becomes D1 2C, etc 2) Convert each hex digit to binary: D1 now becomes 1101 0001 3) Reverse the binary digits in each hex digit (group of 4 bits): 1101 0001 would become 1011 1000 and convert back to Hex Done! So 40 00 37 45 00 01 following the steps above: 1) 04 00 73 54 00 10 2) 0100 0111 0011 0101 0100 0001 3) 0010 1110 1100 1010 0010 1000 Answer: 02ECA20080 If you wanted to have chart to memorize (which is the wuss way out!!), you could even memorize which digits convert to which like: (all numbers in Hex followed by their binary versions in parenthesis) 0 = 0 ( = ) 1 = 8 (0001 = 1000) 2 = 4 (0010 = 0100) 3 = C (0011 = 1100) 4 = 2 (0100 = 0010) 5 = A (0101 = 1010) 6 = 6 (0110 = 0110) 7 = E (0111 = 1110) 8 = 1 (1000 = 0001) 9 = 9 (1001 = 1001) A = 5 (1010 = 0101) B = D (1011 = 1101) C = 3 (1100 = 0011) D = B (1101 = 1011) E = 7 (1110 = 0111) F = F ( = ) In this case, you perform step one to get: 04 00 73 54 00 10 Then use these conversions to get: 02 00 EC A2 00 80 (same as above) If you can use this memorization technique, fine.. But I've said it once, and I'll say it again: This is computers people!!! Computers use binary!!! Networks use binary!!! Digital is binary! If you can't speak binary like a second tongue, then maybe you should rethink your career field This is NOT ROCKET SCIENCE!!! Again, this could be the beers talking. and hopefully someone will get something meaningful out of this post (the memorization chart at the very least) So don't flame me for requesting that people that deal with computers and networking learn binary because binary *is* the language of computers and digital communications and if someone isn't willing to put in the effort to learn it, then they should miss every question on the CCIE or otherwise regarding anything (subnetting, bitswapping, etc) that requires the slightest knowledge of binary!!! Mike W. Hunt Lee wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... I was just wondering if anybody knows a way to translate Ethernet MAC (Cananical) to Token MAC (non-Cananical) vice versa?? I know how to do the simple ones: e.g. 1078.xsxx. HexDec SwapDecHex 10 = 16= 0001 = 1000 = 8 = 08 Or any other ones like DecHex 101 202 303 404 505 606 707 808 909 10 0A 11 0B 12 0C 13 0D 14 0E 15 0F 16 10 17 11 18 12 19 13 20 14 21 15 22 16 23 17 24 18 25 19 But I don't know how to do it if they give me a large one e.g. Hex of 78, or AC etc?? Thanks. Best Regards, Hunt Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=44589t=44578 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: CCIE Written Question [7:44578]
Excellent!!! I hope you don't mind if I steal that for the next book... :-) --- Dennis - Original Message - From: Peter I. Racz To: Sent: Monday, May 20, 2002 7:04 PM Subject: Re: CCIE Written Question [7:44578] Hello, I just want to add my own to what Dennis has said (actually I have learned it from his book too - Thanks Dennis) How can you easily memorize this you may be wondering... 0=0 ( - ) 8=1 (1000 - 0001) 1=8 (0001 - 1000) 9=9 (1001 - 1001) 2=4 (0010 - 0100) A=5 (1010 - 0101) 3=C (0011 - 1100) B=D (1011 - 1101) 4=2 (0100 - 0010) C=3 (1100 - 0011) 5=A (0101 - 1010) D=B (1101 - 1011) 6=6 (0110 - 0110) E=7 (1110 - 0111) 7=E (0111 - 1110) F=F ( - ) Like this: 3 Cats 5 Apples 7 Elefants and DeciBel. These stand for: 3=C (and C=3 of course) 5=A 7=E D=B The rest is really easy to remember because they are very easy to project in your head in binary. 0=0 F=F 6=6 9=9 F=F 1=8 2=4 Good Luck, Peter Peter Ivo Racz Hunt Lee wrote: I was just wondering if anybody knows a way to translate Ethernet MAC (Cananical) to Token MAC (non-Cananical) vice versa?? I know how to do the simple ones: e.g. 1078.xsxx. HexDec SwapDec Hex 10 = 16= 0001 = 1000 = 8 = 08 Or any other ones like DecHex 101 202 303 404 505 606 707 808 909 10 0A 11 0B 12 0C 13 0D 14 0E 15 0F 16 10 17 11 18 12 19 13 20 14 21 15 22 16 23 17 24 18 25 19 But I don't know how to do it if they give me a large one e.g. Hex of 78, or AC etc?? Thanks. Best Regards, Hunt . Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=44596t=44578 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
