From: Church, Chuck (cchurch@netcogov.com)
Date: Wed Feb 02 2005 - 00:04:49 GMT-3
I agree. The NSF (graceful restart) OSPF stuff with sub-second hellos
make for wicked-fast OSPF convergence. Still, I'd rather have 100
devices participating in spanning tree vs. SPF. It's much simpler to
compute. Realistically though, with the fast CPUs in both routers and
switches these days, re-computing SPF vs. recomputing RSTP can't be more
than a second difference one way or another. Both are huge advances
over the 'old' way of doing things...
Chuck Church
Lead Design Engineer
CCIE #8776, MCNE, MCSE
Netco Government Services - Design & Implementation Team
1210 N. Parker Rd.
Greenville, SC 29609
Home office: 864-335-9473
Cell: 703-819-3495
cchurch@netcogov.com
PGP key: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x4371A48D
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Scott Morris
Sent: Tuesday, February 01, 2005 9:33 AM
To: 'Brant I. Stevens'; 'asadovnikov'; 'Conte, Charles';
ccielab@groupstudy.com
Subject: RE: Simple Design Question
On the flip side, you can do OSPF fast hellos and make things equal to
rapid
spanning tree!
Scott Morris, MCSE, CCDP, CCIE4 (R&S/ISP-Dial/Security/Service Provider)
#4713, JNCIP, CCNA-WAN Switching, CCSP, Cable Communications Specialist,
IP
Telephony Support Specialist, IP Telephony Design Specialist, CISSP
CCSI #21903
swm@emanon.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Brant I. Stevens
Sent: Tuesday, February 01, 2005 1:15 AM
To: asadovnikov; 'Conte, Charles'; ccielab@groupstudy.com
Subject: Re: Simple Design Question
I happen to disagree with this direction for the following reasons:
1. Using an IGP as opposed to L2 trunking for an access-to-distribution
link can actually INCREASE reconvergence time, especially when you
consider
the performance of Rapid-PVST and 802.1w. The only exception I've seen
to
this is using EIGRP stub areas @ each access switch, but that means you
have
to run EIGRP, as opposed to OSPF.
2. You will no longer be able to have the same VLAN spread across
multiple
switches (short of using software bridging, which defeats the purpose of
using switches.)
I agree that reducing reliance on STP (even if you could, NEVER disable
it... =)) is always a good idea, but I think L3 to the closet eliminates
some of the benefits that VLANs provide.
On 02/01/2005 12:57 AM, "asadovnikov" <asadovnikov@comcast.net> wrote:
> I like the approach. If access switches are L3 capable you should run
> them as routers not switches. Although there are always corner cases
> when L2 may be better option, I strongly agree that benefits of
> avoiding L2 generally greater then any potential downside.
>
> Best Regards,
> Alexei
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> Of Conte, Charles
> Sent: Monday, January 31, 2005 7:29 PM
> To: ccielab@groupstudy.com
> Subject: OT:Simple Design Question
>
> Hello,
>
>
>
> If MSFC's are available at the access-layer, can anybody
> tell me why we wouldn't run L3 to the access layer if the primary and
> secondary access switches are available in convenient locations? Also
> for the attached gifs can anybody provide any opinions on why one
> wouldn't extend L3 to the access instead of having L2 only Access
> switches [Example 1 L3] V.S. [Example 2 L2]? I like avoiding L2 in
> any situations that I can. I can understand if the requirement is to
> have the vlan available at every switch to go with example 2, but if
> not it wouldn't make sense to extend L2 everywhere. Any opinions
appreciated!
> Thanks!
>
>
>
> Charles
>
> [GroupStudy removed an attachment of type image/gif which had a name
> of example_gif_2.gif]
>
> [GroupStudy removed an attachment of type image/gif which had a name
> of example_gif_1.gif]
>
> ______________________________________________________________________
> _ Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
> ______________________________________________________________________
> _ Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Thu Mar 03 2005 - 08:51:16 GMT-3