From: Kyle Galusha (kgalusha@xxxxxxxxx)
Date: Wed May 09 2001 - 11:30:53 GMT-3
Just for clarity, canonical is ethernet format and noncanonical is token
ring format. Unless my coffee hasn't kicked in.
At 12:53 PM 5/9/2001 +0400, xander wrote:
>Hello Devender,
>
>Multicast addresses begin from bit 1, but in the canonical
>(Token-Ring) notation, so, in Ethernet notation, it will be the last
>bit. Therefore, any kind of MAC that finishes by bit=1 in Ethernet
>notation will be multicast.
>
>Cisco's methos to convert multicast addresses from 23 bits to 32 bits
>is the add 01-00-5e to the begining of 23 bits got from converting
>multicast ip address to hexidecimal notation.
>
>DS> Fred,
>
>DS> I thought the mac addresses for multicast is 01-00-5e-xx-xx-xx. But
>DS> obviously it seems like I am wrong.
>DS> But Tariq's email and your response it seems like multicast mac addresses
>DS> mostly are
>
>DS> 1) 01-00-xx-xx-xx-xx
>DS> 2) but some protocols can also have first octet to be XXXXXXX1- and the
>DS> second octet to XXXXXXXX
>
>DS> Will you be kind enough to clarify this for me.
>
>DS> Devender Singh
>DS> BE(Hons), CCNP
>DS> IP Solution Specialist
>
>
>DS> -----Original Message-----
>DS> From: Fred Ingham [mailto:fningham@worldnet.att.net]
>DS> Sent: Wednesday, 11 April 2001 5:51
>DS> To: Tariq Sharif; Ccielab@Groupstudy. Com
>DS> Subject: Re: MAC Address Filter Examples
>
>
>DS> Tariq: feff will catch any odd number in the second nibble. There are
>DS> protocols that use multicast with an address other than 01 but they are
>DS> all odd.
>
>DS> Cheers, Fred
>
>DS> Tariq Sharif wrote:
> >>
> >> Sorry guys, I was after generic MAC filtering. e.g. with IRB etc not DLSw+
> >>
> >> Ok, here is the question I have:
> >>
> >> R2 has IRB running with 1 Ethernet interface, serial & 1 BVI. Configure an
> >> MAC Address filter on R2 so that it will block broadcast and multicast
> >> packets for a host on its Ethernet Bridge segment. The filter is shown
> >> below. Now why is 1st line in the filter with mask of "feff". I know we
>DS> need
> >> to match multicasts which start with "0100" but shouldn't the mask for
>DS> this
> >> portion be "f0ff" rather than "feff"?
> >>
> >> hostname R2
> >> bridge irb
> >> interface Ethernet1/0
> >> no ip address
> >> bridge-group 1
> >> bridge-group 1 input-pattern-list 1100
> >> !
> >> interface Serial1/0
> >> ip address 140.1.5.2 255.255.255.0
> >> interface BVI1
> >> ip address 140.1.3.2 255.255.255.240
> >> !
> >> bridge 1 protocol ieee
> >> bridge 1 route ip
> >> !
> >> access-list 1100 deny 0000.0000.0000 ffff.ffff.ffff 0100.0000.0000
> >> feff.ffff.ffff
> >> access-list 1100 deny 0000.0000.0000 ffff.ffff.ffff ffff.ffff.ffff
> >> 0000.0000.0000
> >> access-list 1100 permit 0000.0000.0000 ffff.ffff.ffff 0000.0000.0000
> >> ffff.ffff.ffff
> >>
> >> -----Original Message-----
> >> From: Patrick Murphy [mailto:pjm@roadrunner.nf.net]
> >> Sent: 10 April 2001 16:04
> >> To: Tariq Sharif; Ccielab@Groupstudy. Com
> >> Subject: Re: MAC Address Filter Examples
> >>
> >> http://www.cisco.com/warp/public/697/dlswfilter.shtml
> >>
> >> The best I have seen yet!
> >>
> >> Patrick
> >>
> >> ----- Original Message -----
> >> From: "Tariq Sharif" <tariq_sharif@yahoo.com>
> >> To: "Ccielab@Groupstudy. Com" <ccielab@groupstudy.com>
> >> Sent: Tuesday, April 10, 2001 11:49 AM
> >> Subject: MAC Address Filter Examples
> >>
> >> > Does anyone know where I can get MAC Address Filter Examples or info?
> >> >
> >> > Many thanks & regards.
> >> >
> >> > Tariq Sharif
> >> >
> >> > [GroupStudy.com removed an attachment of type application/ms-tnef which
> >> had a name of winmail.dat]
>DS> **Please read:http://www.groupstudy.com/list/posting.html
>--
> WBW, xander
> mailto:xander@adt.ru
> CCNA, CCNP+VoiceAccess,
> CCIE second attempt in Brussels
> 9-10, July, 2001
>
>...
>**Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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