Re: [nsp] Diffrences between buildin and NM 10/100 Ethernet modules

From: Ryan O'Connell (ryan-nsp@complicity.co.uk)
Date: Mon May 27 2002 - 03:31:40 EDT


On Sun, 26 May 2002 14:04:39 +0200 TMS <tomek@absolut.vinyl.pl> wrote:
> Did 10/100 Ethernet interfaces build in above Cisco routers have
> any diffrences between NM 10/100 Ethernet interfaces (ex.NM-1FE2W) ?
> I talking with friend, and He said that build in Ethernet intefaces
> didn't support VLAN encapsulations like dot1q/ISL. My question
> is regarding interfaces in:
>
> 1720
> 2620
> 3661
> 7200VXR I/O Controller with 1 FastEthernet

I believe that most FastEthernet *hardware* supports dot1Q/ISL and all
Ethernet(10Base-T ) hardware does not. IIRC, there are some early FastEthernet
cards out there (Early revisions of the NM-1FE for example) that don't do
it because of firmware limitiations but generally it's true for everything
sold these days.

Beyond that, I think it's software dependant. The 262x, 366x and 7200s are
all certainly capable of dot1Q.

Strangely, CCO claims the 1720 doesn't support dot1Q but that the 1721
does. As the additional cost of the hardware to support dot1Q is probably
minimal, I guess this is a marketing rather than technical limitation.[1]

[1] Compare:
http://www.cisco.com/univercd/cc/td/doc/product/access/acs_mod/1700/1720/1720qsg/intro.htm
and
http://www.cisco.com/univercd/cc/td/doc/product/access/acs_mod/1700/1721/1721hig/1721ovw.htm

--
         Ryan O'Connell - CCIE #8174
<ryan@complicity.co.uk> - http://www.complicity.co.uk

I'm not losing my mind, no I'm not changing my lines, I'm just learning new things with the passage of time



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