Re: FreeBSD, quagga (BGP) and 2950 VLANs

From: Charles Swiger (cswiger_at_mac.com)
Date: 09/19/05

  • Next message: Kurt Jaeger: "Re: FreeBSD, quagga (BGP) and 2950 VLANs" 
    Date: Mon, 19 Sep 2005 13:17:22 -0400
To: Daniel Po*** <daniel@lvdx.com>

    On Sep 19, 2005, at 10:02 AM, Daniel Po*** wrote:
    > I've been told that FreeBSD performs routing computations in linear
    > time, even with large routing tables (such as from BGP), and that
    > it is therefore superior to Linux for use as a border router. Is
    > this so, and are there any specific documents I should review about
    > the performance of FreeBSD routing?

    I believe FreeBSD uses a radix lookup for the routing table which is O
    (1); I don't know enough about the implementation in Linux to make
    claims about one platform being superior.

    > I've discovered that there is the 4.11 release and the 5.4
    > release. Are there any compelling reasons why I should choose one
    > of these over the other, for my intended application? The only
    > application I will be running is quagga.

    If you are setting up a new system, you should go with 5.4. 4.11 is
    older and thus extremely well-tested by now, and might arguably be a
    bit more reliable, but 5.4 has better support for ACPI and recent
    hardware, as well as a significantly better SMP implementation.

    > I'm planning to connect the FreeBSD server to a trunk port on a
    > Cisco 2950 and put each interconnected IP provider into a separate
    > VLAN. The documentation I've read so far suggests that FreeBSD is
    > happy with VLANs - will this arrangement work and will it have any
    > significant effect on performance?

    This ought to work fine, but you might want to make sure your NICs
    supports VLAN_MTU and VLAN_HWTAGGING options to help offload some of
    the work:

    bge0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
             options=1a<TXCSUM,VLAN_MTU,VLAN_HWTAGGING>

    "man 4 vlan" has a more complete discussion, including a list of NICs
    which have this kind of hardware support. The Broadcom bge's and
    Intel's em seem to work well. 

    -- 
-Chuck
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  • Next message: Kurt Jaeger: "Re: FreeBSD, quagga (BGP) and 2950 VLANs"