The MPLS-OPS Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] Re: MPLS-TE tunnel's AFFINITY and MASK configuration
On Tue, Jan 20, 2004 at 10:26:21PM -0800, Harish Kumtakar wrote: > > I've a question for Cisco ppl on the list or anybody who knows Cisco's MPLS-TE configuration. > > The question is related to the configuration of a MPLS-TE tunnel's 'AFFINITY' and 'MASK' parameters. > > Cisco Press book on MPLS-TE (By Eric Osborne) says that "during CSPF path calculation a link considered a match if it satisfies the relation ((AFFINITY & MASK) = = (LINK_ATTRIBUTE & MASK))", where AFFINITY, MASK and LINK_ATTRIBUTE are 32 bit fields (Note: MASK is a collection of do-care bits; this means that if a bit is set to 1 in the MASK, you do care that the bit set in the tunnel AFFINITY string matches the LINK_ATTRIBUTE flags). LINK_ATTRIBUTE flags for a link can be configured using the command 'mpls traffic-eng attribute-flags <0x0-0xFFFFFFFF>'. MPLS-TE tunnel's AFFINITY and MASK parameters can be configured using the command 'mpls traffic-eng affinity <0x-0xFFFFFFFF> [mask <0x-0xFFFFFFFF>]' > > Now, suppose that rightmost 2 bits of LINK_ATTRIBUTE represent the attributes 'attr A' and 'attr B' respectively. Consider simple n/w topology with 3 nodes, > > X-----Y-----Z, > > wherein the link X to Y has only 'attr A' bit set and link Y to Z has only 'attr B' bit set. I want to have a MPLS-TE tunnel from X to Z that must pass through only those links which have either 'attr A' bit or 'attr B' bit or both bits set. I could not find any values for AFFINITY and MASK parameters meeting my requirement and satisfying the above mentioned relation (may be I'm weak in bitwise operations :-)). I would appreciate if you could tell me the values for my tunnel's AFFINITY and MASK parameters. > I'm not sure if there's a way to do this, either; I don't use affinity bits much, but they're designed to look for a specific bit pattern (0x11, 0x10, etc) and what you want is "not 0x00", which is any one of 0x10, 0x01, or 0x11. So it doesn't look possible to me. eric > Thanks, cheers, > > -Harish > > > > --------------------------------- > Do you Yahoo!? > Yahoo! Hotjobs: Enter the "Signing Bonus" Sweepstakes ------- The MPLS-OPS Mailing List Subscribe/Unsubscribe: http://www.mplsrc.com/mplsops.shtml Archive: http://www.mplsrc.com/mpls-ops_archive.shtml
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