RE: dlsw icanreach mac-address 40E0.1E5D.9507 ffff.ffff.ff1f

From: Michael Snyder (msnyder@revolutioncomputer.com)
Date: Mon Feb 09 2004 - 15:31:47 GMT-3


The 0207.78ba.a9e1 was in non-canonical (token ring) I just added
0207.78ba.a9e1 0207.78ba.a9e2
0207.78ba.a9e3 0207.78ba.a9e4

for proof of concept with my masks.

Let's change the question. All four macs are in Ethernet format, write a
dlsw icanreach mac-address command to alert the other dlsw routers that
they can be reached.

40E0.1E5D.9587
40E0.1E5D.9547
40E0.1E5D.95C7
40E0.1E5D.9527

Just working with the common octet (hex mode)

(0x87&0x47&0xC7&0x27) = 0x07 (common number)
(0x87|0x47|0xc7|0x27) = 0xe7 (scope)

0x07 nor 0xe7 = e0 (wildcard)

Mask value= ff-wild = 0xff-0xe0 =0x1f

Answer

dlsw icanreach mac-address 40E0.1E5D.9507 ffff.ffff.ff1f

Can someone check this? I made it up as I went.

Thought it's all based logic I've used before.

When you `and` a set of values, you get the most common element of the
values. When you `or` a set of values you get the greatest scope
(range) of the values. When you `nor` the common against the scope you
get the difference of the two in wildcard format. Total possible value
- wildcard = mask.

-----Original Message-----
From: Scott Morris [mailto:swm@emanon.com]
Sent: Monday, February 09, 2004 8:36 AM
To: 'Calton, Doug'; 'Michael Snyder'; ccielab@groupstudy.com
Subject: RE: dlsw icanreach mac-address 0207.78ba.a9e1

Yup. All DLSW filtering and reachability stuff works in the "token
ring"
format. So you'd have to convert any ethernet MAC addresses that you
have.

 
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713,
CISSP,
JNCIS, et al.
IPExpert CCIE Program Manager
IPExpert Sr. Technical Instructor
swm@emanon.com/smorris@ipexpert.net
http://www.ipexpert.net
 

-----Original Message-----
From: Calton, Doug [mailto:Doug.Calton@getronics.com]
Sent: Monday, February 09, 2004 4:24 AM
To: Scott Morris; Michael Snyder; ccielab@groupstudy.com
Subject: RE: dlsw icanreach mac-address 0207.78ba.a9e1

Assuming this is ethernet, doesn't xlation to non-canonical also kick
in?
Just checking my understanding here.

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Scott Morris
Sent: Sunday, February 08, 2004 10:20 PM
To: 'Michael Snyder'; ccielab@groupstudy.com
Subject: RE: dlsw icanreach mac-address 0207.78ba.a9e1

My vote is with you on the second one...

And apparantly the CCO documents vote the same way!

http://www.cisco.com/en/US/tech/tk331/tk336/technologies_configuration_e
xamp
le09186a0080094135.shtml#config5

So, it must be majority-rule, right? :)

HTH,

 
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713,
CISSP,
JNCIS, et al. IPExpert CCIE Program Manager IPExpert Sr.
Technical Instructor swm@emanon.com/smorris@ipexpert.net
http://www.ipexpert.net
 

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Michael Snyder
Sent: Sunday, February 08, 2004 9:47 PM
To: ccielab@groupstudy.com
Subject: dlsw icanreach mac-address 0207.78ba.a9e1

Trying to come up to speed on dlsw mac filters.

If wanted to accept the following mac`s 0207.78ba.a9e1 0207.78ba.a9e2
0207.78ba.a9e3 0207.78ba.a9e4

Would it be:

dlsw icanreach mac-address 0207.78ba.a9e0 mask 0000.0000.0007

or

dlsw icanreach mac-address 0207.78ba.a9e0 mask ffff.fff.fff8

I think the second one is correct. It's a mask not a wildcard. The hex
makes it harder to figure. (I did 255-7 and converted back to hex) Thank
God
I had that 6502 machine language course years ago.



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