Fwd: VLAN Troubles

Ryan Malayter malayter at gmail.com
Tue Mar 6 23:46:24 UTC 2012



On Mar 6, 11:53 am, david peahi <davidpe... at gmail.com> wrote:
>
> Why don't you replace the Dell switches with Cisco 3560s, and that way you
> are working with a single implementation of the IEEE 802.1q trunking
> standard? I think the very existence of this email thread proves that much
> time and effort is wasted in the attempt to seamlessly interoperate devices
> from multiple vendors. In this email thread alone I counted 2 CLI's to be
> learned, 2 tech support organizations to call, and 2 hardware types to
> spare.
>
> David

Funny, it's always the Cisco devices that seem to be the cause of
interop problems in my network. They're the only vendor that seems to
think defaulting proprietary protocols is reasonable. Cat 3ks default
to proprietary Rapid-PVST+, proprietary VTP, proprietary DTP,
proprietary HSRP, and proprietary ISL tagging. And Cisco documentation
generally recommends these proprietary protocols or at least documents
them *before* the standard equivalents (wonder why?). Cisco does of
course generally support the IEEE or IETF protocols, but not without
configuration that often requires downtime or at least a spanning-tree/
OSPF event if it was missed before deployment.

We can lash together Dell/HP/other switches all day long with near-
default configurations, but every time we have a new Cisco box to
configure it's required to wade though IOS release notes to see what
new proprietary protocol we have to disable.

Cisco makes good gear with lots of features, but can be a royal pain
if you use *anything* non-Cisco. It's not prudent to rely on a single
vendor for anything, and it's not as though IOS is a magically bug-
free bit of code.

I've been told that in at least some high-frequency trading networks,
the redundant switches/routers at each tier are intentionally from
different vendors, so that a software issue in one won't take
everything down. That seems like a good idea at first, but it wouldn't
surprise me to have an interop issue or mis-configuration caused by
unfamiliarity take down both devices. Does anybody out there do this?




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