Re: [nsp] ISL and 802.1q trunk

From: Everett Dowd (edowd@clark.net)
Date: Thu Sep 21 2000 - 12:19:57 EDT


Anything that doesn't have a "Cisco" label... I have it running on

    Cat 5500
    Cat 6509
    Cat 6006
    Cat 2900M and 2900c
    Cat 4003

Oleg Kostine wrote:

> Once again,
> what are the "NON Cisco" devices is it 29xx,35xx or 5x000 or 6x00 or
> 7200/7500 or 12000???
> Cheers
> Oleg
>
> -----Original Message-----
> From: Everett Dowd [mailto:edowd@clark.net]
> Sent: 21 September 2000 15:48
> To: Oleg Kostine
> Cc: 'Dmitri Kalintsev'; cisco-nsp@puck.nether.net
> Subject: Re: [nsp] ISL and 802.1q trunk
>
> Hmmm,
>
> I disagree cause I am using only dot1q STP and I have a STP instance for
> each
> VLAN... It is an enhancement that I have heard is trying to make it into the
> dot1q standard... If you connect "NON Cisco" devices you can only have a
> single
> instance of STP but if you are using all Cisco equipment, multiple instances
> work just fine...
>
> Everett
>
> Oleg Kostine wrote:
>
> > One little detail:
> > If you use 802.1q on Cisco you have only one STP domain for all vlans over
> > the trunk.
> > 29xx,35xx or 6x00 manuals is a good source for more info.
> >
> > -----Original Message-----
> > From: Dmitri Kalintsev [mailto:dek@hades.uz]
> > Sent: 20 September 2000 12:57
> > To: cisco-nsp@puck.nether.net
> > Subject: Re: [nsp] ISL and 802.1q trunk
> >
> > On Wed, Sep 20, 2000 at 06:07:48PM +0800, Cho Man Fai wrote:
> > >
> > > Dear all,
> > >
> > > Can ISL and 802.1q trunk exist in the same network? Any workaround to do
> >
> > Sure they can. One little detail - if you run VLANs with numbers higher
> than
> > 1000 when you use 802.1q, you'll have to manually map them into lower
> > numbers
> > when you need them to cross ISL trunk.
> >
> > > so without changing the whole network to 802.1q? What's the pros and
> cons
> > > of the two trunking protocol?
> >
> > 802.1q is an industry standard, though not all cisco catalysts support it.
> > 802.1q will support up to 4096 VLANs, where ISL will support only 1024 (or
> > 1000? correct me if I'm wrong). ISL does not really care about "native
> VLAN"
> > for trunk port, 802.1q does - it must match on both sides of the trunk or
> > you'll get lost packets.
> >
> > In general, the answer probably is "use 802.1q where you can, and ISL
> where
> > you must".
> >
> > SY,
> > --
> > CCNP,CCDP (R&S) Dmitri E. Kalintsev
> > CDPlayer@irc Chief of Network Operations @ Sonorous Networks
> > dek @ hades.uz phone: +27 11-327-1524 fax: 327-7648
> > http://hades.uz UIN:7150410 cell +27 82-336-1033
>
> --
> <><><><><><><><><><><><><><><><><><><><><><><><><><><>
> "Failure is not an option"
> Gene Cranz, Apollo 13 mission
> <><><><><><><><><><><><><><><><><><><><><><><><><><><>
> Everett Dowd edowd@clark.net
> CCIE #2409 http://www.clark.net/pub/edowd
> Just bein' virtual =8^) Welcome to the 'net
> |_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|

--
<><><><><><><><><><><><><><><><><><><><><><><><><><><>
"Failure is not an option"
                  Gene Cranz, Apollo 13 mission
<><><><><><><><><><><><><><><><><><><><><><><><><><><>
Everett Dowd              edowd@clark.net
CCIE #2409                http://www.clark.net/pub/edowd
Just bein' virtual =8^)   Welcome to the 'net
|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|



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