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nure

@telus.net

RE: can a l3 switch with full dynamic protocol set

setting used as a router, like 3620? I mean the IOS, not the hardware.

thanks?


belushi
Premium,MVM
join:2000-11-08
Twinsburg, OH
Depending on the device a layer 3 switch can absolutely be used as a router. That's pretty much the definition of a layer 3 switch. Obviously its ability to handle full routing protocols depends on the version and IOS in use. Generally enhanced image layer 3 switches like 3560s, 3550s, 4500s, 6500s to name a few can handle very robust routing protocols. Some of the switches even come with the options to install very robust WAM interfaces.

I almost hesitate to even call a 6500 a switch nowadays with all the different modules you can install into it. Cisco is making it kind of like an all encompassing device for routing, switching, firewall,IDS, IPS, voice, video, etc. The lines between devices are surely being blurred as time progresses.


nure

@imagefoundation.com
Hi,thanks, when you say
"Generally enhanced image layer 3 switches like 3560s, 3550s, 4500s, 6500s to name a few can handle very robust routing protocols"
do you mean, that they can route between their interfaces.
because i thought 3550 can't
thanks
nure


belushi
Premium,MVM
join:2000-11-08
Twinsburg, OH
I thought you were talking about a switches ability to handle dynamic routing protocols like EIGRP, RIP, OSPF, etc. These switches can do it, but generally you need enhanced image capability over regular standard image. Mostly the standard image layer 3 switches can only handle static routing and basic layer 3 functionality. It totally depends on the switch though.

I don't have a 3550 in front of me, but I know with a 3560 you can turn a switchport into a layer 3 port with the "no switchport" command.


rolande
Certifiable
Premium,Mod
join:2002-05-24
Dallas, TX
kudos:6
Reviews:
·AT&T U-Verse
·ViaTalk

Re: RE: can a l3 switch with full dynamic protocol

The 3550 works exactly the same way with just a different, "less capable" backplane architecture than the 3560. It can run with VLAN interfaces and route like a traditional Layer3 switch or you can use the no switchport command and turn a FastE interface into a Layer3 port. In that case, you can apply port ACLs directly to a layer3 port as well.

The 3550 can run pretty much any routing protocol. The only one I think not supported is IS-IS. Other than that it has a fairly full blown IOS implementation and can pretty much do most anything you would need.
--
Ignorance is temporary...stupidity lasts forever!


Monster Rain
Premium
join:2002-08-03
Madison, WI
said by rolande:

The 3550 can run pretty much any routing protocol. The only one I think not supported is IS-IS.
You thought right
ISIS can't be run on the 3550's, but you can on say, for example, the 3750's.


sporkme
drop the crantini and move it, sister
Premium,MVM
join:2000-07-01
Morristown, NJ
reply to belushi

Re: RE: can a l3 switch with full dynamic protocol set

One thing I'm curious about in the L3 switch world... Back in the day there was a huge worm that had a side effect of rendering many "layer 3" switches useless. Once the worm hit, it tried to spread, and in the process of scanning for other hosts to infect it would flood these layer 3 switches' arp tables (pushing "good" entries, like upstream routers out of the forwarding table) and the switch would fall back to no longer doing flow-based forwarding, but per-packet forwarding.

Since many vendors at that point were playing up the flow-based PPS/Mb/s numbers and playing down the non-flow-based routing, lots of folks discovered that routers were best used in many cases.

Has this situation changed in the last few years?
--
enjoy zesty ranch man-flavored baby tacos responsibly


rolande
Certifiable
Premium,Mod
join:2002-05-24
Dallas, TX
kudos:6
Reviews:
·AT&T U-Verse
·ViaTalk

Re: RE: can a l3 switch with full dynamic protocol

Well you can always use NBAR to kill a good worm. But if you have a 6500 platform with an MSFC, the newer MSFC's are pretty much off-shoots of the 7200 NPE's. I believe the MSFC on a SUP720 is equivalent to an NPE-G1 which can put up some really hefty numbers. So they have a lot of horsepower and memory capability. On the smaller end, you can get burnt pretty badly in a situation like that because the processors are not scaled to handle process switching in the volumes you'd be seeing..
--
Ignorance is temporary...stupidity lasts forever!


nure

@ncix.com
reply to nure

Re: RE: can a l3 switch with full dynamic protocol set

Basically what I need a l3 switch and a router for experiement. Since I already have a couple of router now, and I dont have any switch yet. I just want to save my space by buying a switch that can used as a router like 3600 series, I only need ehterbet ports.

So I can use 3550 as a router in experiments like BGP,OSPF or EIGRP?
Do I need EMI?
thanks,

nure

aryoba
Premium,MVM
join:2002-08-22
kudos:4
Specifically for Catalyst 3550, you do need to run the EMI for the OSPF and BGP since the SMI only run RIP (and maybe EIGRP).

Keep in mind that the 3550 does not have to be the original EMI since SMI 3550 are capable to run EMI. Physically the original SMI and EMI are the same thing. The only different is the original IOS (which is either SMI or EMI). However you can upgrade SMI 3550 to run EMI whenever necessary.


nure

@telus.net
Do 3550s come with SMI or SMI is an option when you purchase 3550s?
thanks,
nure

aryoba
Premium,MVM
join:2002-08-22
kudos:4
Only from software (Cisco IOS images) point of view, Cisco produces two kind of Catalyst 3550. They are SMI and EMI version. When you buy Catalyst 3550 switches, you have option to buy either the SMI or EMI version.

SMI version are for "smaller organizations". Whenever these organizations feel ready to upgrade, they can upgrade their SMI 3550 to run EMI version.

EMI version are for "larger organizations" obviously. Therefore when the need to have EMI are present already, then those organizations can just buy the EMI version directly without dealing with SMI-to-EMI-upgrade process.

Note that there are a lot of original SMI 3550 switches that already run EMI version for sale. Therefore when you need the EMI 3550, you have choices to buy either the original EMI or the upgraded SMI-to-EMI. From performance point of view, they are exactly the same. The only difference between them is their original software.


nure

@telus.net
are the prices significantly different between 3550-SMI and 3550-EMI?
thanks,


rolande
Certifiable
Premium,Mod
join:2002-05-24
Dallas, TX
kudos:6
Yes.


nure

@telus.net
reply to nure
Power supply part number: 34-0966-04
Model revision number: P0
Motherboard revision number: A0
Model number: WS-C3550-24-EMI

Does this mean EMI is installed?
thansk,


nure

@telus.net
reply to nure
Guys, according to what you said, the following one can work as router to support dynamic protocols. but the documents about it says nothing about it. I would like confirm this one can work as a router thansk,

»www.cisco.com/en/US/products/hw/···dex.html


TomS_
Git-r-done
Premium,MVM
join:2002-07-19
London, UK
kudos:5
To quote that page you mentioned:

"The Catalyst 3550 24 EMI provides:

* 24 10/100 ports and 2 GBIC-based Gigabit Ethernet ports
* 1 rack unit (RU) stackable multilayer switch with full dynamic IP routing
* Delivers intelligent services
* Enhanced Multilayer Software Image (EMI) installed"

Its right at the bottom of the page. How hard did you look?


nure

@telus.net
Thanks,
the point is I think I dont understand EMI too much. now that you've mentioned this, then I would spend some time reading it.

By the way, is it safe to buy 3550 switch on Ebay?

thanks,


TomS_
Git-r-done
Premium,MVM
join:2002-07-19
London, UK
kudos:5
reply to nure
EMI = Enhanced Multilayer Image. Basically it has the greatest number of features for both switching and routing.

The 3550's go for $1-2 thousand generally (from what I have seen anyway).

You may find one chepaer, but it will be a rat race to win it, and it will probably end up around the same price as the others.