From: Chuck Church (cchurch@MAGNACOM.com)
Date: Fri Sep 27 2002 - 15:13:55 GMT-3
Weidong,
Is your 'provider' giving you trunks, or just a single VLAN? If
you're not negotiating a trunk between 1 and 11, and between 2 and 22, it'll
never work because VTP advertisements won't be sent from your equipment. I
think you're going to need some info from your provider. If they provide
intra-building connectivity for multiple companies, it sounds like they just
give each company a VLAN. But it'd be easy for them to give you a few
VLANs, 2 trunks, and prune all VLANs not belonging to you off your 2 trunks.
I think you've got to talk to them first.
Chuck Church
CCIE #8776, MCNE, MCSE
Sr. Network Engineer
Magnacom Technologies
140 N. Rt. 303
Valley Cottage, NY 10989
845-267-4000
-----Original Message-----
From: Weidong Xiao [mailto:Weidong.Xiao@vi.net]
Sent: Friday, September 27, 2002 12:44 PM
To: Chuck Church
Cc: Lyndon Guo; ccielab@groupstudy.com; Phil; Bob Rech; Ahamed Maideen
Subject: RE: VTP
Thanks for your reply.
I wish that I could have contral on Switch 11 and 12. In fact they are not
our CPE.
If the VTP stuff can't work the way as I said, we have to pay an arm and leg
for a inter-floor link, or set up 2 vtp domains, involving network
changing...
I heard from my colleague from his friend's friend that it might work. I
think the best way to verify it is to do an experiment.
Does someone have spare switches and could be kindly do a test?
Cheers,
Weidong
> -----Original Message-----
> From: Chuck Church [mailto:cchurch@MAGNACOM.com]
> Sent: 27 September 2002 15:46
> To: Weidong Xiao; 'Phil'; 'Bob Rech'; 'Ahamed Maideen'; 'Lyndon Guo'
> Cc: 'ccielab@groupstudy.com'
> Subject: RE: VTP
>
>
> Why not just leave all connections as trunks, and make
> switches 11 and 22
> VTP transparent? That way they'll forward the VTP
> advertisements unchanged.
> I'm assuming from the drawing that 11 and 22 are both in domain 2. If
> either 11 or 22 need to be a client or server, I don't think
> it'll ever
> work. VTP is a special kind of packet, like CDP. A Cisco
> device won't just
> switch/route it like a normal frame/packet. They get send to
> the CPU. If a
> VTP advertisement's domain doesn't match your domain, it's
> ignored and not
> forwarded.
>
> Chuck Church
> CCIE #8776, MCNE, MCSE
> Sr. Network Engineer
> Magnacom Technologies
> 140 N. Rt. 303
> Valley Cottage, NY 10989
> 845-267-4000
>
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Weidong Xiao
> Sent: Friday, September 27, 2002 8:25 AM
> To: Phil; Bob Rech; Ahamed Maideen; Lyndon Guo
> Cc: ccielab@groupstudy.com
> Subject: RE: VTP
>
>
> Thanks you all for your reply, but I still think there may be
> a chance for
> it to work.
>
> Say, SW1 send a frame to Sw11, ISL encapsulated. The
> beginning of this frame
> is a 26 bytes ISL header, and the beginning of this ISL header is
> destination address field. This address is a multicast
> address and is set
> at "0x01-00-0C-00-00" or "0x03-00-0c-00-00". The next field
> in ISL header is
> Type Field, for ethernet, it's always 0000. So, from Sw11
> (vlan8 port)point
> of view , the first 48 bits of the frame it received is
> "0x01-00-0C-00-00-00" or "0x03-00-0c-00-00-00". This is a
> multicast mac
> address, if the Sw11 port is doing cut-through switching (or whatever
> switching), the port should flood it all over vlan8, so the
> frame should be
> able to arrive SW2.
>
> Does this make sense?
>
> Thank you very much,
> Weidong
>
> p.s.
> URL about isl encapsulation frame format:
> http://www.cisco.com/warp/public/473/741_4.html
>
>
>
>
> > -----Original Message-----
> > From: Phil [mailto:ciscostudent1@yahoo.com.br]
> > Sent: 26 September 2002 17:31
> > To: Weidong Xiao; ccielab@groupstudy.com
> > Subject: Re: VTP
> >
> >
> > I don't believe it's gonna work. VTP, as the name states
> > (Vlan Trunk Protocol) is supposed to run on trunks.
> >
> > Weidong Xiao <Weidong.Xiao@vi.net> escreveu: Hello,
> >
> > SW1----------------Sw11--Sw22-----------SW2
> > (domain1,server) (domain2) (domain1,client)
> >
> > I have four switches belonging to 2 domains, topoly is as
> > above. Is it possible for vlan information propagate from SW1
> > to SW2? If I create a vlan (say,vlan8)in domain2, can I deem
> > vlan8 just as a wire, and it should transport vtp info?
> >
> > Cheers,
> > Weidong
> >
> >
> > ---------------------------------
> > Yahoo! GeoCities
> > Tudo para criar o seu site: ferramentas faceis de usar,
> > espago de sobra e acesssrios.
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