Modern Hubs actually switched?

Archived from groups: comp.dcom.lans.ethernet (More info?)

I am trying to capture unicast traffic from host A to host B by using
host C to sniff on a Linksys 5-port Hub (the newest Linksys/Cisco version).

However it seems this hub is not acting as a repeater. A promiscuous
host C will not detect unicast traffic that is not intended for it.

I've tried various nodes to be the promiscuous host to see if it was a
datalink issue, but I get the same results.

Also the hub's activity lights will only blink for the sending and
receiving unit when packets are transmitted.

We've seen this on 3 modern devices labeled as hubs.

Has anyone else experienced this with modern "hubs"?

Is it now just cheaper to make all devices switching and then label some
as hubs as others as switches?

-Brian
2 answers Last reply
More about modern hubs switched
  1. Archived from groups: comp.dcom.lans.ethernet (More info?)

    gorby <gorbster@cc.gatech.spam.edu> wrote:
    >Has anyone else experienced this with modern "hubs"?

    That's been true for at least a year now. You have to look for really
    old gear that you know is hub-based, usually in the used market (eBay,
    etc) to find real hubs now-adays.

    >Is it now just cheaper to make all devices switching and then label some
    >as hubs as others as switches?

    Indeed. Also, most folks who are buying them don't know the
    difference. With the exception of this one use, they aren't in a lot
    of demand, and a managed switch will let you do this (at a
    significantly higher price...)
  2. Archived from groups: comp.dcom.lans.ethernet (More info?)

    William P.N. Smith wrote:
    > gorby <gorbster@cc.gatech.spam.edu> wrote:
    >
    >>Has anyone else experienced this with modern "hubs"?
    >
    >
    > That's been true for at least a year now. You have to look for really
    > old gear that you know is hub-based, usually in the used market (eBay,
    > etc) to find real hubs now-adays.
    >
    >
    >>Is it now just cheaper to make all devices switching and then label some
    >>as hubs as others as switches?
    >
    >
    > Indeed. Also, most folks who are buying them don't know the
    > difference. With the exception of this one use, they aren't in a lot
    > of demand, and a managed switch will let you do this (at a
    > significantly higher price...)
    >
    I have a gripe about this. I spend a lot of time troubleshooting and
    taking packet captures. When port mirrors and spanned ports do not cut
    the mustard, I sometimes rely on 100Mb/s shared hubs to inject analyzers
    in the middle of a dataflow. Without shared hubs, and the ability to
    mirror ports, I am left with purchasing expensive taps. Good thing most
    hubs will run forever...

    -mike
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