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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Any 1U - 2U Ethernet switches that can handle 4K VLANs?
On Sun, Jan 25, 2004 at 09:39:05PM +0100, Mikael Abrahamsson wrote: > This is interesting, what problems did you run into? > > We have an extensive Extreme networks used both for L2 and L3, and apart > from the fact that it always cpu routes ICMP, I see no major flaw in the > L3 forwarding function (for access/distribution) for all normal purposes. ACLs are per-port and known to be buggy when operating on port numbers - in particular UDP ACLs match will match arbritary data when presented with a subsequent IP fragments (think NFS...) As pointed out in a similar thread recently, the 'flow-based' (well, destination IP based) ipfdb will crap out on the Extremes under heavy load - e.g. virus'd machines internal to your network doing heavy scanning. Symptom is very poor performance and the 'top' command will show heavy CPU usage as subsequent flows are CPU routed. > My few experiences with the Cisco 3550 as L3 routers has been much worse, > even with claimed CEF capability I have seen it melt and die where the > equivalent Extreme box didnt experience the same problems (of course there > are cases where it's the other way around). Overall I have more confidence > in the Extreme access boxes for L3 than Ciscos equivlanent, and they > definately kick ciscos ass when it comes to L2 (mac address table size and > number of vlans for instance). The 'recommended max' number of SVIs for the 3550 is something low like 8. There is no limited stated in the datasheet for the 3750 - is anyone running more than 8 SVIs on a 3750? The ACL capability on the 3550 seems a lot more capable but the lack of unicast RPF is irritating. (More irritating, 'ip verify unicast reachable-via...' is accepted but silently does nothing) I'd be very interested to hear what conditions you've found cause problems for Cat3550s. We're planning to buy quite a few more of this range (probably 3750-24) to reduce L2 size in our network and for CPE-type uses.
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