Bill, Hex is equivalent to Base16 numbering. Decimal is really Base10 numbering. Let's look at an example of Base10 numbering broken down into it's components, then we'll tackle your examples..
The decimal number 4243 drawn out in Base10 is as follows: (4x10^3) + (2x10^2) + (4x10^1) + (3x10^0) ... Let's do the math... 4x1000 + 2x100 + 4x10 + 3x1 = 4243 Simple, right? So hex is exactly the same, except you use powers of 16 and the letters A-F map to numbers 10-15 respectively. Let's do your examples... F00: Fx16^2 + 0x16^1 + 0x16^0 ...Let's do the math... 15x256 + 0x16 + 0x1 = 3840 ...Voila! Youve just converted Hex to decimal. Now how does that give us the Ring/Bridge #'s?...First, you need to understand that the Route Descriptor is broken down like this: RRRRRRRRRRRRBBBB, where R=Ring# and B=Bridge# Given that FOO in Binary is only 12 bits but the field above is 16 bits, we have to pad the left side with 0's so as not to change the value (Though it's not displayed this way.) This makes it 0x0F00. In binary, this is: 0x0F00 = 0000111100000000 This means that the Ring is 000011110000 and the Bridge is 0000 when you break the fields apart. Convert this binary back to decimal, you get Ring#=3840, Bridge#=0, (The bridge bits set to all 0's means "the ring local to the destination). Valid bridge #'s are 1-15. Your second example: 2F2 = 0x02F2 = 0000001011110010 = Ring 000000101111 / Bridge 0010 = Ring# 47/Bridge# 2 If you had a RIF that read 0810.02F2.0F00, then the RIF would translate to this: 0810(Routing control bits).Ring47/Bridge2.Ring3840/Bridge0(or ring local to destination) Hope this helps. Kelly Cobean, CCNP, CCSA, ACSA, MCSE, MCP+I Network Engineer -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Mckenzie Bill Sent: Thursday, March 14, 2002 9:02 AM To: [EMAIL PROTECTED] Subject: Hex to Decimal for the RD [7:38223] Could someone help me get a clear understanding of converting the hex number to a nice decimal ring number or bridge number. Two examples that have me stumped are: F00 and 2f2. Thanks Everyone in advance. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38245&t=38223 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
