From: Lupi, Guy (Guy.Lupi@xxxxxxxxxxxxx)
Date: Thu Apr 18 2002 - 11:50:11 GMT-3
Sure, if you want to do it the "EASY" way. But I like to live on the edge,
just kidding :). I see what you are saying, but what if the mac address is
not live and they ask you to do a filter or dynamic peering based on it? In
that situation you would have to know what to do without being able to see
the format.
~-----Original Message-----
~From: DAN DORTON [mailto:DHSTS68@dhs.state.il.us]
~Sent: Thursday, April 18, 2002 10:44 AM
~To: frank@buff-net.com; Lupi, Guy
~Cc: ccielab@groupstudy.com
~Subject: RE: bitflipping in dlsw - when?
~
~
~The easiest way to determine this is to do a show dlsw reachability.
~
~Find out what format the remote address is in. ;)
~
~Dan
~
~>>> "Lupi, Guy" <Guy.Lupi@eurekaggn.com> 04/18/02 09:07AM >>>
~That is an interesting statement, but I believe that any dlsw
~filtering/dynamic peering that is mac based should be in non canonical
~format. The dlsw router will convert the mac back to canonical for
~transmission to the endstation (I believe it has to), but filtering or
~dynamic peering is done on the non-canonical address. I have
~tested this
~with dynamic peers and Mamoor's dspu setup, when specifying
~the canonical
~mac address as the dest-mac for the peer, it never comes up.
~As soon as you
~change it to non-canonical, it works, I tested it between 2
~ethernet peers.
~Now, I am no dlsw guru, so I could be wrong here, but from all
~the testing I
~have done this is what I have found. In the event that you
~are filtering on
~the interface for the bridge group, I believe the filter would use the
~canonical address. I will test it later and let you know.
~
~~-----Original Message-----
~~From: Frank B [mailto:frank@buff-net.com]
~~Sent: Wednesday, April 17, 2002 7:29 PM
~~To: Lupi, Guy; 'CCIE Groupstudy'
~~Subject: RE: bitflipping in dlsw - when?
~~
~~
~~If you filter this mac address somehwere in the path between the two
~~Ethernet segments (after it's picked up by DLSW) you're correct.
~~
~~But DLSW coverts the mac back to canonical if the destination is an
~~Ethernet segment. So, "what if" you were filtering traffic inbound to
~~the destination segment from a DLSW peer connection across a WAN such
~~as:
~~
~~router(config-if)#bridge-group 2 input-address-list 700
~~
~~Is the conversion back to canonical made at point this already? What
~~would be the proper address format for access-list 700? Does anyone
~~know? Please copy me on the reply if you do.
~~
~~Frank
~~
~~-----Original Message-----
~~From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On
~Behalf Of
~~Lupi, Guy
~~Sent: Wednesday, April 17, 2002 11:07 AM
~~To: 'Adam Atkinson'; CCIE Groupstudy
~~Subject: RE: bitflipping in dlsw - when?
~~
~~Someone will correct me if I am wrong I am sure, but I believe
~~that even
~~if
~~the filtering is ethernet to ethernet the mac address must be swapped.
~~When
~~looking at an ethernet router that has dlsw configured, even the local
~~mac
~~addresses that it picks up will be shown in non-canonical
~~format. So if
~~your workstation has mac address 1111.1111.1111, it will appear on the
~~local
~~dlsw router as 8888.8888.8888. So if filtering for a mac address that
~~is on
~~an Ethernet segment, you always bitswap it when you put it in the
~~filter.
~~Below is an example of what I am talking about, r2 is a dlsw
~router and
~~r8
~~is on the Ethernet segment. R8's show interface is below, notice the
~~mac
~~address, and then look at the dlsw reach information on r2.
~~R2 has that
~~mac
~~address in non canonical format.
~~
~~r8#sh int e0/0
~~Ethernet0/0 is up, line protocol is up
~~ Hardware is AmdP2, address is 0002.16d9.c460 (bia 0002.16d9.c460)
~~
~~r2----E0----r8
~~
~~r2#sh dlsw reach
~~DLSw Local MAC address reachability cache list
~~Mac Addr status Loc. port rif
~~0040.689b.2306 FOUND LOCAL TBridge-001 --no rif--
~~
~~DLSw Remote MAC address reachability cache list
~~Mac Addr status Loc. peer
~~
~~DLSw Local NetBIOS Name reachability cache list
~~NetBIOS Name status Loc. port rif
~~
~~DLSw Remote NetBIOS Name reachability cache list
~~NetBIOS Name status Loc. peer
~~
~~r2#
~~
~~
~~
~~-----Original Message-----
~~From: Adam Atkinson [mailto:ghira@mistral.co.uk]
~~Sent: Wednesday, April 17, 2002 2:55 PM
~~To: CCIE Groupstudy
~~Subject: bitflipping in dlsw - when?
~~
~~
~~I'm feeling less than clear on _when_ I need to to bitflip the MAC
~~address I'm given in a dlsw-related assignment.
~~
~~If the mac address is from an ethernet segment, and I'm
~~filteing on a TR
~~segment, I bitflip.
~~
~~Are there other situations where I'd need to do this?
~~
~~--
~~Adam Atkinson (ghira@mistral.co.uk)
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:58:12 GMT-3