Re: Any 1U - 2U Ethernet switches that can handle 4K VLANs?

[Will Hargrave <will () harg net>]

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.