dslreports logo
 
    All Forums Hot Topics Gallery
spc
uniqs
15
aryoba
MVM
join:2002-08-22

aryoba to cramer

MVM

to cramer

Re: Cisco switch into non-cisco switch, unknown initial lag

said by cramer:

said by flq06:

layer 2 (only) switches doesn't keep any ARP info.

Yes they do; you just cannot see it on an unmanaged switch.

Layer-2 switch has no knowledge of IP address or anything concerning Layer-3 and up since Layer-2 switch deals with only MAC addresses. Therefore Layer-2 switch maintains CAM or MAC address table which correlate between MAC address and certain switch port. ARP Table keeps correlation between IP address and MAC address which typically Layer-3 capable devices maintain such as Layer-3 switch and router.

An exception is IGMP snooping feature where Layer-2 switch is capable to snoop Layer-3 info of Multicast group in order to associate the Multicast MAC address (as a result of the Multicast group translation from Layer-3 IP address to Layer-2 MAC address) with certain switch ports where the Multicast subscribers connect.
said by cramer:

Unless it's flooding every packet to every port all the time (which would make it a HUB), it does have tables of MAC's known to be on each port.

Layer-2 switches typically do not flood packets, however they flood frames since the switches only talk Layer-2.