""Priscilla Oppenheimer"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > [EMAIL PROTECTED] wrote: > > > > Hi all, > > > > I can't for the life of me remember what the recommended > > maximum number of clients on one segment is, I think it was > > either 300 or 500. > > It depends. Cisco has some guidelines on this that are based mostly on a > concern for broadcast traffic. Although broadcast traffic doesn't tend to > eat a lot of bandwidth (they are often short packets), each broadcast packet > interrupts the CPU on all devices in the broadcast domain. So Cisco > recomendations are based on the protocols in use and how much broadcast > traffic they tend to use. (Cisco also icludes multicast traffic in the > equation because when they made the guidelines, a lot NICs were stupid about > multicasts and passed them to the host CPU, even if they weren't relevant, > and the driver had not registered to receive them.) > > IP is 500 > IPX is 300 > AppleTalk is 200 > NetBIOS is 200 > Mixed is 200
Every time this discussion comes up, I'm reminded of my interview at Major Well Known Bank a couple of years back. They told me they had shared segments of as many as 1200 stations. The engineering staff was EXPERT in sniffer analysis and broadcast suppression. They could track down a NIC that was sending out more than what they determined to be "acceptable" keepalives, and replace it within minutes!!!! All stations used only one app - an internal privately developed app for banking transactions. IP based, but client server in nature. I didn't know then, but I presume now that ARP traffic was at a minimum because of this situation. > > So memorize those numbers for the CCDA test ;-), but, of course also do some > real analysis of your actual network. > > I have seen real-world evidence of broadcast traffic causing older PCs to > slow down. But if your netework has GHz processor PCs, it may not matter one > bit that they get disturbed by a lot by broadcasts!? > > Also, those numbers from Cisco are pretty dated. These days switches with > full-duplex ports are so cheap, you can have most of your LAN "segments" > with just two nodes on them! (The PC and the switch port) > > In addition to considering broadcast traffic, you should also consider how > much load each device is going to generate and the devices' sending > patterns, as someone else mentioned. On shared Ethernet, it gets pretty ugly > if a lot of stations are sending very frequently. A significant portion of > the bandwidth gets wasted on frames that don't go anywhere. Instead they > collide with other frames. > > Priscilla > > > > > > > Can anyone confirm ? > > > > Cheers, > > > > Graham. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=49713&t=49704 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
