[66813] in North American Network Operators' Group
Re: Any 1U - 2U Ethernet switches that can handle 4K VLANs?
daemon@ATHENA.MIT.EDU (sthaug@nethelp.no)
Mon Jan 26 12:11:26 2004
To: phill@andrew.cmu.edu
Cc: nanog@merit.edu
From: sthaug@nethelp.no
In-Reply-To: Your message of "Mon, 26 Jan 2004 11:52:06 -0500"
Date: Mon, 26 Jan 2004 18:08:43 +0100
Errors-To: owner-nanog-outgoing@merit.edu
> > 1) Cisco ISL is much better than urgly 802.1q - first of all, it was
> > designed many years before 802.1q. I am not even talking abiout those
> > idiots, who designed 802.1q as a _spanning tree on the trunk level_,
> > which
> > made many configurations (which we used with ISL ain 199x years)
> > impossble,
> > and caused vendors to extend 802.1q.
>
> Is it April 1st? ISL changes the size of packets, does it not? So know
> you have to deal with MTU issues. What happens when I want the biggest
> MTU possible? I know it is not much a difference in size, but for some
> people, size does matter.
>
> I am quite happy with dot1q. My gripe is with poor spanning-tree
> implementations. I don't want a single spanning-tree for every vlan on
> a trunk... I like standards, but I am happy with Rapid-PVST. Just my
> feelings about the issue. I would never deploy ISL unless I had
> something like a 1900 that did not do dot1q
Amen. At my previous employer, we got rid of ISL on almost all trunks.
I wouldn't dream of going back. The only thing I don't really like about
802.1q compared to ISL is the idea of "native" or "default" VLAN. I want
links to be either access (untagged) or trunk (*all* packets tagged).
Fortunately, reasonably new Cisco switches let me enforce that with
"vlan dot1q tag native".
Steinar Haug, Nethelp consulting, sthaug@nethelp.no
