Question regarding Catalyst 35xx

Discussion in 'Cisco' started by JB, Nov 3, 2003.

  1. JB

    JB Guest

    Hi all.
    I'm looking at the functionnlity of the Catalyst 35xx series and I'm
    asking a question.
    To set my problem let me introduce my platform :
    - I've tree kind of station connected over 3 differents networks.
    - some are part of a public network, other of a private one and all
    are part of the management network.
    - the problem is that all this machine only have 1 NIC over the one
    I declare 2 or 3 IP addresses from different IP network to distinguish
    public/private and management network.

    My problem is to define correctly my VLANs knowing that some station
    need to communicate with machine of other VLAN.
    I've already made nearly the same thing using Nortel switch that all
    a port to belong to multiple VLAN. But if my meory is good I think CISCO
    can't do that.
    - Is it true ?
    - If yes does the routing capability of the 35xx allow us to have
    the same throuput that pure switching ? I know that 65xx routing capabilties
    allow the switch to determine the exit port after solve the routing and
    after this make only switching for layer packet matching the previous
    packet.

    Thanks to all.

    --
    JB.
    ==============================================================
    It's a pleassure to learn when teachers are full of knowledge and
    wisdom.
    ==============================================================
     
    JB, Nov 3, 2003
    #1
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  2. Program ended abnormally on 03/11/2003 05:49, Due to a catastrophic JB
    error:
    > Hi all.
    > I'm looking at the functionnlity of the Catalyst 35xx series and I'm
    > asking a question.
    > To set my problem let me introduce my platform :
    > - I've tree kind of station connected over 3 differents networks.
    > - some are part of a public network, other of a private one and all
    > are part of the management network.
    > - the problem is that all this machine only have 1 NIC over the one
    > I declare 2 or 3 IP addresses from different IP network to distinguish
    > public/private and management network.


    It depends on the model. The newer 3550s can do layer 3 routing and therefore
    have multiple IP addresses, but the older models were only layer 2 switches.
    The fact that the switch only has 1 ip address doesn't prevent you from
    configuring multiple vlans on it, though, you'll just have to have an external
    router or firewall provide the routing between vlans.

    >
    > My problem is to define correctly my VLANs knowing that some station
    > need to communicate with machine of other VLAN.
    > I've already made nearly the same thing using Nortel switch that all
    > a port to belong to multiple VLAN. But if my meory is good I think CISCO
    > can't do that.
    > - Is it true ?


    That depends, you could configure frame tagging if your device supports it or
    configure all your ports in the same vlan, but configure some of them "protected".

    > - If yes does the routing capability of the 35xx allow us to have
    > the same throuput that pure switching ? I know that 65xx routing capabilties
    > allow the switch to determine the exit port after solve the routing and
    > after this make only switching for layer packet matching the previous
    > packet.
    >


    I can't comment on the performance of L3 vs. L2 for a 3500, I'm sure Cisco's web
    site has numbers that can help you.

    > Thanks to all.
    >
    > --
    > JB.
    > ==============================================================
    > It's a pleassure to learn when teachers are full of knowledge and
    > wisdom.
    > ==============================================================
    >
    >
    >


    --
    Francois Labreque | The surest sign of the existence of extra-
    flabreque | terrestrial intelligence is that they never
    @ | bothered to come down here and visit us!
    videotron.ca | - Calvin
     
    Francois Labreque, Nov 3, 2003
    #2
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  3. JB

    JB Guest

    "Francois Labreque" <> wrote in message
    news:%4tpb.34430$...
    >
    >
    > Program ended abnormally on 03/11/2003 05:49, Due to a catastrophic JB
    > error:
    > > Hi all.
    > > I'm looking at the functionnlity of the Catalyst 35xx series and I'm
    > > asking a question.
    > > To set my problem let me introduce my platform :
    > > - I've tree kind of station connected over 3 differents

    networks.
    > > - some are part of a public network, other of a private one and

    all
    > > are part of the management network.
    > > - the problem is that all this machine only have 1 NIC over the

    one
    > > I declare 2 or 3 IP addresses from different IP network to distinguish
    > > public/private and management network.

    >
    > It depends on the model. The newer 3550s can do layer 3 routing and

    therefore
    > have multiple IP addresses, but the older models were only layer 2

    switches.
    > The fact that the switch only has 1 ip address doesn't prevent you from
    > configuring multiple vlans on it, though, you'll just have to have an

    external
    > router or firewall provide the routing between vlans.


    I think we will look at the 3550.

    > >
    > > My problem is to define correctly my VLANs knowing that some

    station
    > > need to communicate with machine of other VLAN.
    > > I've already made nearly the same thing using Nortel switch that

    all
    > > a port to belong to multiple VLAN. But if my meory is good I think CISCO
    > > can't do that.
    > > - Is it true ?

    >
    > That depends, you could configure frame tagging if your device supports it

    or
    > configure all your ports in the same vlan, but configure some of them

    "protected".

    The problems is that our stations are on Linux and we cannot use 802.1q
    tag's at the source.
    It'll be great if it was the case.

    What do you say by "protected" ???

    > > - If yes does the routing capability of the 35xx allow us to

    have
    > > the same throuput that pure switching ? I know that 65xx routing

    capabilties
    > > allow the switch to determine the exit port after solve the routing and
    > > after this make only switching for layer packet matching the previous
    > > packet.
    > >

    >
    > I can't comment on the performance of L3 vs. L2 for a 3500, I'm sure

    Cisco's web
    > site has numbers that can help you.


    I've found my anwser.
    In all case really thanks.

    > > Thanks to all.
    > >
    > > --
    > > JB.
    > > ==============================================================
    > > It's a pleassure to learn when teachers are full of knowledge and
    > > wisdom.
    > > ==============================================================
    > >
    > >
    > >

    >
    > --
    > Francois Labreque | The surest sign of the existence of extra-
    > flabreque | terrestrial intelligence is that they never
    > @ | bothered to come down here and visit us!
    > videotron.ca | - Calvin
    >
     
    JB, Nov 3, 2003
    #3
  4. JB

    Scooby Guest

    Yes, you just have to remember to enter the command 'ip routing' to turn
    that feature on - which is not on by default.

    Routing at switching speeds? Probably not exactly, but close. To route a
    packet, it still needs to rewrite the header which will take some time.
    However, there are different ways to cache routes and depending upon which
    method you select will depend upon your performance gain. Turn on CEF and
    you will get the close to switching speeds - I believe that is on by default
    in the Cisco L3 switches.




    "JB" <> wrote in message
    news:bo5bsn$...
    > Hi all.
    > I'm looking at the functionnlity of the Catalyst 35xx series and I'm
    > asking a question.
    > To set my problem let me introduce my platform :
    > - I've tree kind of station connected over 3 differents networks.
    > - some are part of a public network, other of a private one and

    all
    > are part of the management network.
    > - the problem is that all this machine only have 1 NIC over the

    one
    > I declare 2 or 3 IP addresses from different IP network to distinguish
    > public/private and management network.
    >
    > My problem is to define correctly my VLANs knowing that some

    station
    > need to communicate with machine of other VLAN.
    > I've already made nearly the same thing using Nortel switch that

    all
    > a port to belong to multiple VLAN. But if my meory is good I think CISCO
    > can't do that.
    > - Is it true ?
    > - If yes does the routing capability of the 35xx allow us to have
    > the same throuput that pure switching ? I know that 65xx routing

    capabilties
    > allow the switch to determine the exit port after solve the routing and
    > after this make only switching for layer packet matching the previous
    > packet.
    >
    > Thanks to all.
    >
    > --
    > JB.
    > ==============================================================
    > It's a pleassure to learn when teachers are full of knowledge and
    > wisdom.
    > ==============================================================
    >
    >
    >
     
    Scooby, Nov 3, 2003
    #4
  5. In article <%4tpb.34430$>,
    Francois Labreque <> wrote:
    :It depends on the model. The newer 3550s can do layer 3 routing and therefore
    :have multiple IP addresses, but the older models were only layer 2 switches.

    Francois, could you expand on that?

    Digging around Cisco's site, I do see a *small* number of references
    to 3550XL switches as being somehow distinct from Catalyst 3550.
    I cannot find any product literature for them, though. One
    third-party page I found hinted that the 3550XL might be the 3550-12T.

    Digging more through Cisco's site, the earliest 3550 software support
    I can find is IOS release 12.1(4)EA1. Nothing before 12.1(11)EA is
    indexed by the Feature Navigator, but it was possible to search for
    the release specifically in cisco.com after I found its name.

    http://www.cisco.com/en/US/customer...1833/products_tech_note09186a008012594a.shtml

    Cisco IOS(R) Software Release 12.1(4)EA1 is optimized for Layer 2
    and Layer 3 switching on the Catalyst 3550 platforms. This release
    is based on Cisco IOS Software Release 12.1(4)E. This release is
    the first introduction of the Catalyst 3550 hardware platform.
    Catalyst 3550 is targeted as an access layer switch which provides
    comprehensive Quality of Service (QoS) and Security access control
    list (ACL) support as well as IP routing.

    None of the 3550XL references I can find predate the above document
    (May 2001).

    In short, I cannot seem to find any evidence that there was ever
    a 3550 that only supported Layer 2 and did not support Layer 3 ?
    --
    100% of all human deaths occur within 100 miles of Earth.
     
    Walter Roberson, Nov 3, 2003
    #5
  6. Program ended abnormally on 03/11/2003 12:53, Due to a catastrophic
    Walter Roberson error:

    > In article <%4tpb.34430$>,
    > Francois Labreque <> wrote:
    > :It depends on the model. The newer 3550s can do layer 3 routing and therefore
    > :have multiple IP addresses, but the older models were only layer 2 switches.
    >
    > Francois, could you expand on that?
    >


    Sorry for the confusion, I meant to say "older switches in the 35xx series", not
    older 3550 models.

    Since the original poster used the words "the Catalyst 35xx series" I didn't
    want to assume he was looking at buying new equipment.

    --
    Francois Labreque | The surest sign of the existence of extra-
    flabreque | terrestrial intelligence is that they never
    @ | bothered to come down here and visit us!
    videotron.ca | - Calvin
     
    Francois Labreque, Nov 4, 2003
    #6
  7. In article <%4tpb.34430$>,
    Francois Labreque <> wrote:
    :program ended abnormally on 03/11/2003 05:49, Due to a catastrophic JB
    :error:

    :> - If yes does the routing capability of the 35xx allow us to have
    :> the same throuput that pure switching ?

    :I can't comment on the performance of L3 vs. L2 for a 3500, I'm sure Cisco's web
    :site has numbers that can help you.

    Yes, at the Data Sheets.
    http://www.cisco.com/en/US/products/hw/switches/ps646/products_data_sheet09186a00800913d7.html

    Look in "Table 2 Product Specifications". In a recent thread about the
    Nortel Baystack 470 vs the Cisco 3550, we saw that the slowest of the
    3550 models has a forwarding rate about twice that of the Baystack 470.
    The figures for the 3550 for Layer 2 and Layer 3 are indicated as
    being the same as each other; Layer 3 is NOT noted as being slower
    than Layer 2.

    --
    Rome was built one paycheck at a time. -- Walter Roberson
     
    Walter Roberson, Nov 4, 2003
    #7
  8. JB

    Andre Beck Guest

    "Scooby" <> writes:
    >
    > Yes, you just have to remember to enter the command 'ip routing' to turn
    > that feature on - which is not on by default.


    Sure? Not even on the fat EMI ones like the 3550-12G/T? I simply cannot
    remember, if it was off by default, activating it seems to be a reflex
    already ;)

    > Routing at switching speeds? Probably not exactly, but close. To route a
    > packet, it still needs to rewrite the header which will take some time.


    Anyone know how exactly the 3550/3750 implement routing? Is it the same
    method as used by the 65xx where the first packet of a new flow addressed
    to a switch MAC is routed by the CPU/TCAM and for the following packets,
    a header patch is installed that just rewrites some L2 and L3 fields?
    There is some close hint that it may be this way: EtherSVI interfaces
    just count a trickle of the real routed bandwidth, something that seems
    to correspond well with only the first packet of every flow (and the 3550
    design was probably too cheap to work around this, while the 65xx found
    a way to count that traffic correctly)...

    > However, there are different ways to cache routes and depending upon which
    > method you select will depend upon your performance gain. Turn on CEF and
    > you will get the close to switching speeds - I believe that is on by default
    > in the Cisco L3 switches.


    Actually, AFAIR, it is not only on by default, you cannot even switch it
    off. They use a TCAM based hardware implementation of CEF that you simply
    cannot avoid. The CPU in these boxes would be way too slow to actually
    route packets at gigabit speeds. The only drawback of that concept is
    that the TCAM capacity is too small for todays DFZ routes plus a medium
    amount of IGP, beeing silent of tomorrows. With just two address bits
    more and some fixes, those boxes would be *awesome* - so they are just
    cool.

    --
    The _S_anta _C_laus _O_peration
    or "how to turn a complete illusion into a neverending money source"

    -> Andre "ABPSoft" Beck +++ ABP-RIPE +++ Dresden, Germany, Spacetime <-
     
    Andre Beck, Nov 6, 2003
    #8
  9. JB

    Steinar Haug Guest

    [Andre Beck]

    | > Yes, you just have to remember to enter the command 'ip routing' to turn
    | > that feature on - which is not on by default.
    |
    | Sure? Not even on the fat EMI ones like the 3550-12G/T?

    Not even on the 3550-12G by default. I assume the -12T is the same.

    Steinar Haug, Nethelp consulting,
     
    Steinar Haug, Nov 7, 2003
    #9
  10. On 07 Nov 2003 00:25:51 +0100, Andre Beck <> wrote:

    >Anyone know how exactly the 3550/3750 implement routing? Is it the same
    >method as used by the 65xx where the first packet of a new flow addressed
    >to a switch MAC is routed by the CPU/TCAM and for the following packets,
    >a header patch is installed that just rewrites some L2 and L3 fields?


    It sounds like you're referring to MLS, which is what the Sup1A on the
    6500's uses. Newer 6500 Sup's are all ASIC-based CEF these days
    AFAIK. The 3550 seems to be as well.

    -Terry
     
    Terry Baranski, Nov 8, 2003
    #10
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