From: Victor Kasacavage (vkasacavage@xxxxxxxxxx)
Date: Thu Aug 10 2000 - 10:57:39 GMT-3
Phillip,
If only network design were that easy.....in the real world things such as
politics and budget creep into the design and generally dictate it. Enough
on that though.....
If you use L3 routing as described below at the distribution layer, why not
just trunk the 4908G's and do away with the 6500's all together? That
doesn't answer you question though........the question is about performance
using the L3 switch vs Layer 2 switch.....I will state that generally there
won't be a performance difference in this scenario with either switch, thus
making the L2 switch the logical choice because it should be less expensive.
Why would there be no performance difference.....with the information given,
the server farm is attached to the core....most traffic will be client
server based, not client to client, so therefore most traffic would be going
to the core and L3 switching will provide very little benefit for the cost
at the distribution layer. This is a generalization of course and your
mileage may vary.
HTH
Victor
----- Original Message -----
From: "Philip Lai" <philip.lai@ncr.com>
To: <ccielab@groupstudy.com>
Cc: "Philip Lai" <philip.lai@ncr.com>
Sent: Thursday, August 10, 2000 9:22 AM
Subject: CCIE Design Candidate , Pls read.
> Network Design issue.
>
> 6500(L3)- 6500 (L3) Core
> / \
> 4908G(L3) 4908G(L3) Distribution
> / \ / \
> 2924M 2924M 2924M 2924M Access
> A B C D
> Vlan1 Vlan2 Vlan3 Vlan4
>
> Server Farm will be directly attached to the Core. There will be some
> departmental servers in zone A for both zone A and B users.
>
> My friend has designed a switching network like this and claim that it
will
> have better performance than using 3508G (L2) in the distribution layer.
> Since the 4908G has the L3 routing feature, when zone A transfer packet to
> zone B, that traffic will pass only the 4908G but not the 6500 (Core).
Thus,
> the bandwidth from the 6500 to 4908G can be saved.
>
> My questions:
> 1. If both the Core and Distribution switch are routing enabled, that
> switches has to be the VTP server. ie: 4 indentical Vlan database are keep
> by each switches (Core & Dist.)
> 2. Does it meaningful to configure trunk mode between all switches in
order
> to pass the Vlan information ? If all 2924M are in VTP clients mode,
which
> switches should be the VTP server ? and why?
> 3. A crazy idea is to think about the L3 switches as a individual router.
> Then apply OSPF between to each one and enable routing. Will the network
be
> quite slow for this design, compared with the standard design.-- Core
> (Routing)--Dis(Switching)---Access(Switching) ?
>
> 4. In fact, I recommend the stand design using 3508G for dist. But could
you
> tell me the adv and Disadv for using this and the design above ?
>
> Thank you very much for every reply
>
> Philip Lai
>
>
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:24:23 GMT-3