From: jonatale@xxxxxxxxxxxxx
Date: Tue Aug 21 2001 - 03:22:13 GMT-3
note that it is defined as the first bit transmitted, which in t/r is the MSb
(same thing with the LLC SAP (not to be confused w/ IPX SAP))
Karelis, Pete (2507) wrote:
> The low order bit of the first octet in an ethernet mac address sets weather
> it is a Layer 2 Multicast or not.
>
> Any MAC address that has an odd number in the first octet is indeed A
> multicast MAC address, it's just not THE Multicast MAC Addresses used by
> IP....
>
> -Pete Karelis
>
> -----Original Message-----
> From: Chuck Church [mailto:cchurch@MAGNACOM.com]
> Sent: Monday, August 20, 2001 1:35 PM
> To: 'BRZYSKI, ADAM E (SWBT) '; 'Bob Chahal '; 'Daniel C. Young '; Chuck
> Church; 'ccielab@groupstudy.com '
> Subject: RE: ipx routing 1111.1111.1111
>
> Those are the ones that make a valid translation to a class D IP address.
> Notice that they all start with 01:, indicating the group bit is set. As
> long as the group address bit is set, devices will see the frame as a
> non-unicast.
>
> Chuck
>
> -----Original Message-----
> From: BRZYSKI, ADAM E (SWBT)
> To: Bob Chahal; Daniel C. Young; 'Chuck Church'; ccielab@groupstudy.com
> Sent: 8/20/01 10:33 AM
> Subject: RE: ipx routing 1111.1111.1111
>
> I though that the range of mac's reserved for multicasts falls in the
> following range:
>
> 01:00:5e:00:00:00 - 01:00:5e:7f:ff:ff
>
> that would not explain why 1111.1111.1111 would not work on a loopback
> interface.
>
> Adam Brzyski
> Design Engineer II
> CCNP, CCDP, NNCDE
>
> -----Original Message-----
> From: Bob Chahal [mailto:bob.chahal@ntlworld.com]
> Sent: Monday, August 20, 2001 3:54 AM
> To: Daniel C. Young; 'Chuck Church'; ccielab@groupstudy.com
> Subject: Re: ipx routing 1111.1111.1111
>
> Chuck, thanks for the reminder. I keep forgetting about this.
>
> Daniel, in a lab scenario you are very likely to be asked to configure
> an
> IPX network on a loopback.
>
> Thanks for the replies.
>
> Bob
> ----- Original Message -----
> From: "Daniel C. Young" <danyoung99@mediaone.net>
> To: "'Chuck Church'" <cchurch@MAGNACOM.com>; "'Bob Chahal'"
> <bob.chahal@ntlworld.com>; <ccielab@groupstudy.com>
> Sent: Monday, August 20, 2001 5:26 AM
> Subject: RE: ipx routing 1111.1111.1111
>
> > Also Bob,
> >
> > With IPX, you don't need to worry about putting networks on loopbacks.
> Think
> > about it, IPX is a desktop protocol for connecting LANs. I've never
> had a
> > problem with using the 'ipx routing 1.1.1' convention.
> >
> > Regards,
> > Daniel
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> > Chuck Church
> > Sent: Sunday, 19 August 2001 4:01 PM
> > To: 'Bob Chahal'; 'ccielab@groupstudy.com'
> > Subject: RE: ipx routing 1111.1111.1111
> >
> >
> > Bob,
> >
> > You're defining a multicast address. This is from
> > http://www.cisco.com/warp/customer/473/85.shtml#multicast :
> >
> > Note: Recall that the least significant bit of the most significant
> octet
> of
> > an Ethernet or FDDI MAC address is the "group bit." If the bit is set
> (1),
> > the MAC address is a
> > multicast (or broadcast). If the bit is not set (0), the MAC address
> is a
> > unicast. The MAC address 0900.3333.4444 has the group bit set, and is
> > therefore a multicast
> > MAC (09 hex = 00001001; the last bit, the group bit, is set).
> >
> > Chuck
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> > Bob Chahal
> > Sent: Sunday, August 19, 2001 5:16 PM
> > To: ccielab@groupstudy.com
> > Subject: ipx routing 1111.1111.1111
> >
> >
> > When I configure a router with
> >
> > ipx routing 1111.1111.1111
> >
> > and then configure a loopback
> >
> > int lo0
> > ipx netw 10
> >
> > if I do a show ipx int lo0 the ipx address is 10.1111.1111.1111
> >
> > if I then ping this address from the same router (i.e the router on
> which
> > this is configured) my pings timeout.
> >
> > If I do not configure an address with the ipx routing command the ipx
> add
> of
> > the lo0
> > uses tha mac address of the ethernet interface on the router and when
> I
> now
> > ping the lo0 it works
> >
> > p 10.0010.7bfe.6cc1
> > Translating "10.0010.7bfe.6cc1"
> >
> > Type escape sequence to abort.
> > Sending 5, 100-byte IPX cisco Echoes to 10.0010.7bfe.6cc1, timeout is
> 2
> > seconds:
> >
> > !!!!!
> > Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
> >
> >
> > Can anyone explain why this happens. I was thinking of configuring my
> ipx
> > routers like the first method above as it makes configuring
> frame-relay
> > maps easier to configure and troubleshoot but the side-effect is what
> I
> just
> > described.
> >
> > Thanks
> >
> > Bob
> > **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
> **Please read:http://www.groupstudy.com/list/posting.html
> **Please read:http://www.groupstudy.com/list/posting.html
> **Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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