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Switch connected to hub

mahesh18
Level 6
Level 6

Hi all,

if switch port is connected to hub and we have 2 pc connected to hub.

if we do sh mac-address on switch with

MAc- address of each pc will it show same

port for 2 different mac address for pc?

also if user pn pc 1 is sending data to pc 2 how data will go directly via hub only or will it go to hub then to switch

and then to hub and users.

will cam table entries show both pc mac address or hub mac address on the incoming port?

many thanks

3 Accepted Solutions

Accepted Solutions

Jon Marshall
Hall of Fame
Hall of Fame

Mahesh

"will it show same

port for 2 different mac address for pc?"

Yes the switch port will show both PC mac-addresses.

A hub sends data out of all ports except the port the data came in on so if PC1 sends data to PC2 then the data will not have to go "via" the switch altho the switch port will also receive the traffic in addtion to PC2.

Jon

View solution in original post

Edison Ortiz
Hall of Fame
Hall of Fame

if we do sh mac-address on switch with

MAc- address of each pc will it show same

port for 2 different mac address for pc?

Yes.

also if user pn pc 1 is sending data to pc 2 how data will go directly via hub only or will it go to hub then to switch

and then to hub and users.

Data will remain in the hub.

will cam table entries show both pc mac address or hub mac address on the incoming port?

Both PCs. Most Hubs have no intelligence (no MAC address).

__

Edison.

View solution in original post

Giuseppe Larosa
Hall of Fame
Hall of Fame

Hello Mahesh,

the sh mac-address-table interf type x/y will show two entries

the switch knowing that both MAC addresses are out the same port will perform MAC address filtering and will not forward frames originated from PC1 and destinated to PC2 to other switch ports in the same Vlan.

For how the hub works each frame is sent out all other ports with the exclusion of the receiving port.

you will never see the hub mac address unless it has a management TCP/IP stack:

the hub is simply an electrical repeater that obliges to work in half duplex for what I write above: it replicates a frame out all other ports

Hope to help

Giuseppe

View solution in original post

4 Replies 4

Jon Marshall
Hall of Fame
Hall of Fame

Mahesh

"will it show same

port for 2 different mac address for pc?"

Yes the switch port will show both PC mac-addresses.

A hub sends data out of all ports except the port the data came in on so if PC1 sends data to PC2 then the data will not have to go "via" the switch altho the switch port will also receive the traffic in addtion to PC2.

Jon

Edison Ortiz
Hall of Fame
Hall of Fame

if we do sh mac-address on switch with

MAc- address of each pc will it show same

port for 2 different mac address for pc?

Yes.

also if user pn pc 1 is sending data to pc 2 how data will go directly via hub only or will it go to hub then to switch

and then to hub and users.

Data will remain in the hub.

will cam table entries show both pc mac address or hub mac address on the incoming port?

Both PCs. Most Hubs have no intelligence (no MAC address).

__

Edison.

Giuseppe Larosa
Hall of Fame
Hall of Fame

Hello Mahesh,

the sh mac-address-table interf type x/y will show two entries

the switch knowing that both MAC addresses are out the same port will perform MAC address filtering and will not forward frames originated from PC1 and destinated to PC2 to other switch ports in the same Vlan.

For how the hub works each frame is sent out all other ports with the exclusion of the receiving port.

you will never see the hub mac address unless it has a management TCP/IP stack:

the hub is simply an electrical repeater that obliges to work in half duplex for what I write above: it replicates a frame out all other ports

Hope to help

Giuseppe

mahesh18
Level 6
Level 6

Hi ,

Thanks all for great timely reply to answer my question

Many thanks

Mahesh

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