>>>>> On Mon, 24 Jan 2000 16:03:20 +0000, "Neil J. McRae" <neil@COLT.NET> said:
Neil> On Mon, 24 Jan 2000 10:06:01 -0500 (EST)
Neil> Tony Tauber <ttauber@bbnplanet.com> wrote:
>> The other problem we've seen is input ignores when SRAM on
>> the VIPs isn't that high (2MB) and there's lots of traffic
>> bound for one or two busy output pipes (like the normal aggregation
>> box) with high numbers of input interfaces (like a box loaded with
>> CT3s). Due to the way the buffers are carved, any given channel on
>> the CT3 gets not too much memory.
>> Watch out for VIP2-40s (can't carry more than 2MB) or cards
>> based on them like the CT3IP (vs. PA-MC-T3 with a VIP2-50).
>> Looks like upping the SRAM to 4 or 8MB works much better.
Neil> We've seen that on ATM PA-A3's with lots of sub interfaces,
Neil> the solution was to lower the MTU. Although remember not
Neil> to change the MTU on a live box.
Talk a bit about changing the mtu on a live box? I tried to up the mtu
from 1500 to 4470 on a live interface, and it did not seem to take effect.
(was having ospf db distribution issue with Juniper on the other end that
had default 4470 mtu, and ended up setting the Juniper down to 1500
instead.)
Considering buffering, would 1500, which is mostly datagram size anyway, be
wiser that 4470 default?
Dave.
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