From: AdebolaA@mtnnigeria.net
Date: Tue Sep 07 2004 - 12:29:55 GMT-3
Dustin, he does not need a full internet table, it all depends on his policy
with his ISP. He could do it with the 2600 if for example he gets his ISP to
send him only a small or jut a default route. You seemed to miss the fact
that all he wants to use BGP for is dynamic failover. I believe James needs
the failover capability and not route specifics. He can achieve this even
with the IPS send him a default route, after all he will always exit via the
ISP. I get the impression James that you are multiple connections to the
same ISP not different ISPs?
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
dusth@comcast.net
Sent: 07 September 2004 15:14
To: Devi Mallampalli; ccielab@groupstudy.com
Subject: Re: Layer 3 switches(3550s/3750s) vs Routers (2651XMs)
Devi,
We have several 6509 w/ MSFC-2 layer 3 switches as the internet router, and
connect direct to several 100MB pipe via ethernet direct form ISP with no
problem at all.
Qos and traffic shaping still work well. However, you stated you like to run
BGP, then 2651 and 3750 will not do the job. You need more powerfull router
like 7204 and up - but 7200 series are EOL.
You will need alot of memory and CPU intensive router to run BGP on your
router in the real world BGP peer w/ your ISP.
Good luck
Dustin
-------------- Original message --------------
> Hi Group,
>
> Got a real world scenario at hand and would like to gather your thoughts
> on this :-)
>
> I am seriously planning to replace our Internet Router/2651 and its
> expensive 2MB Frame circuit with that of Layer 3 switch (either 3550 or
> 3750) and with lesser expensive 2 MB BDSL (Business DSL) WAN circuit
> which is delivered on to "Ethernet" port on layer 3 switch directly.
> The primary reason of doing this design is to not only to derive direct
> cost savings to the tune of around US$20k per annum (Yes, 4MB HSSI
> installation cost and per annum usage cost are too high when compared to
> a 2 MB BDSL Ethernet circuit) to our corporation , but also to try out
> alternative WAN protocols which can delivered on to an Ethernet/RJ45
> interface rather than on x25 or v35 interfaces (with a long term view to
> replace all Routers on our WAN with that of Layer 3 switches with an
> MPLS core and BDSL combination at remote sites so that we can move away
> with our current HUB and SPOKE Frame relay WAN and instead can have one
> flat , one hop away WAN. Any way that is different story)
>
> But before I proceed I just want to have a second opinion on whether or
> not it is a good idea to assign Internet periphery responsibility to a
> Layer 3 switch , rather than a decent Router such as 2651 XM , primarily
> from both Qos and required Redundancy point of view.
>
> Qos , because I am not 100% on whether or not I can do Shaping ,
> Policing , Policy Routing and IP Routing on Ethernet interfaces of
> 3550/3750 to the same "Degree" as that of Routers/2651XM serial
> interfaces ? And more over , I was wondering with this Layer 3 design ,
> I will be loosing congestion indicators such as DEs, BECNs and FECNs on
> the wire and so from what features I can take help on Ethernet WAN
> interfaces(well in my case it is BDSL which is being delivered on to a
> RJ 45 interface at customer premises) to the similar effect ?
>
> Redundancy , since our Internet infrastructure need to support critical
> Ecommerce apps, originally I thought of deploying a back up 2651 as well
> and then run BGP between them and our ISP's Internet edge routers.
> Unlike our current static routing , I was planning to extract more
> effective dynamic fail over between two Routers from L3 protocol/BGP. In
> addition , from L3 protocol I am hoping to do some traffic engineering
> in terms of preferred "outbound" and "inbound" in to our AS. And I am
> not 100% on whether I can do the same things on Layer 3 switches ?
>
> I have seen 3550s operating happily on our N/W in doing roles such as
> "Campus Vlan router" and "switch block aggregator" for 20 odd 7960 IP
> phones ...etc. But I have not seen them in the role of perimeter Routing
> device in doing both Routing functions as well as advanced Qos.
>
> I am inclined towards Layer 3 switching design because 1) we can
> eliminate routers costs 2) it will save us Telco circuit costs as well
> since we are not using expensive WAN protocols such as Frame/HSSI.
>
> But I appreciate any feed back on the intended solution.
>
> Cheers
>
> Devi.
>
>
>
>
>
>
>
>
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