Cisco PIX 515E bottlenecks Comcast High Speed Internet

Discussion in 'Cisco' started by ryan_condon@yahoo.com, Aug 27, 2008.

  1. Guest

    I just switched from a T1 to Comcast HighSpeed Internet 16mb/6mb. I
    am using a Cisco PIX 515E as our firewall. With the firewall in the
    works between my laptop and Comcast I get at best 5mb/5mb speeds using
    Speakeasy speed testing. When I remove the PIX from the equation I
    consistently get 10mb/5mb. I lose on average between 3-5mb when I put
    the PIX in the middle. It does not make any sense. I consider
    configuring the hardware properties of the Outside NIC as far as
    Duplex and Speed and that didn't make a difference.

    I know this is not a bandwidth limitation of the PIX so it has to
    either be a setting on the PIX or something in the interaction between
    the Comcast router and the PIX.

    Pease help!
    , Aug 27, 2008
    #1
    1. Advertising

  2. In article <>,
    <> wrote:
    >I just switched from a T1 to Comcast HighSpeed Internet 16mb/6mb. I
    >am using a Cisco PIX 515E as our firewall. With the firewall in the
    >works between my laptop and Comcast I get at best 5mb/5mb speeds using
    >Speakeasy speed testing. When I remove the PIX from the equation I
    >consistently get 10mb/5mb. I lose on average between 3-5mb when I put
    >the PIX in the middle. It does not make any sense. I consider
    >configuring the hardware properties of the Outside NIC as far as
    >Duplex and Speed and that didn't make a difference.


    Are you accidently blocking Path MTU Discovery by not
    explicitly permitting ICMP Fragmentation Needed packets into
    your network? Such packets could have an IP address of anywhere
    between the source and destination, so effectively you have to
    permit "any" for their outside source, and you have to effectively
    permit as the destination any of your internal machines that can
    go out to the internet.
    Walter Roberson, Aug 28, 2008
    #2
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Walter Roberson

    Re: PIX 515E and eMule with HIGH ID

    Walter Roberson, Apr 1, 2004, in forum: Cisco
    Replies:
    0
    Views:
    1,101
    Walter Roberson
    Apr 1, 2004
  2. DannyD1355

    USB High Speed against USB Non High Speed

    DannyD1355, Sep 7, 2003, in forum: Computer Support
    Replies:
    1
    Views:
    571
    Patrick
    Sep 7, 2003
  3. david ramon

    Re: "Comcast Mail" <>

    david ramon, Oct 22, 2003, in forum: Computer Support
    Replies:
    1
    Views:
    991
    trout
    Oct 22, 2003
  4. news.xtra.co.nz
    Replies:
    2
    Views:
    685
    news.xtra.co.nz
    Apr 20, 2006
  5. Nancy
    Replies:
    1
    Views:
    711
    kaiqiang
    Jun 26, 2009
Loading...

Share This Page