Matthew Petach wrote: > > As I understand it, (and Cisco's documentation seems to support this, > http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2ZY/command/reference/M1.html#wpxref54198 > as an example), if you put a /128 in an ACL, you cannot specify any L4 port > information for the address due to the limited width of the TCAM; in > order to specify L4 information for the ACL, Cisco stuffs it into bits 24 > through 39, losing what information was originally stored in those bits. > It just so happens those are the fixed FFFE bits in an EUI-64 address, > so if you're using EUI-64, no "real" information is lost. You can do your > own non-EUI-64 addressing and still use ACLs with layer 4 port information > as long as you don't put any addressing information into bits 24 through 39. >
Interesting; makes sense though. Thanks for the explanation. ~Seth
