switching method of 3500 series

[dwhaga]

does the 3512/3524/3548 support cut-through

switching or store-n-forward.

we need cut-through switching for a project we are

working on.

[bsivasub]

It does store-n-forward. why do you need cut-through anyway ? Store-n-forward is superior.

[dwhaga]

this may sound funny, but we don't want packets to

get dropped when they have errors (i.e. runts,

giants, CRC, etc.)

we are developing a system for commercial airplanes

and have hosts talking to each other over dedicated

10BT Ethernet links.

we need the switch to allow us to "break" the

point-to-point links, and allow the insertion of

a LAN analyzer and other test devices while

maintaining the "direct wire" like link.

we also like the fact that CT switches have lower

packet latency.

[bsivasub]

what you need is a hub (or other lower end switches)!!!

:)

[dwhaga]

yes, we considered a hub.

what we are doing is using the switch to "break" into

multiple point-to-point LAN segments, each on it's

own IP network number.

if I use a hub, this will combine the broadcast

domains of all the segments, introduce collisions,

reduce our duplex bandwidth to simplex, and degrade

performance of the otherwise directly wired segments.

the switch is going to be used for instrumentation

and test of our network and needs to "preserve" the

original nature of the direct wire segments.

we also have requirements for VLANs, SPAN port, etc.

intending to use VLAN's (in order to separate the

broadcast domains of the unique LAN segments), I am

also trying to figure out if a Cisco switch is able

to configure a SPAN port made up of ports on separate

VLAN's.