[j-nsp] MX and microbursting...
All: I have a Cisco 7206VXR w/NPE-G2 attached to an MX. The issue I am seeing is ignored packets on the 7200. It turns out, the 1G interfaces on the NPE-G2 have 128 packet rx-rings and this is not a tunable thing. I have tuned up buffers and hold-queues on the 7200 and this has drastically reduced the number of dropped packets, but still there is this rx-ring limitation. This is actually a fairly well known issue as I understand it. Is there anything I could do on the MX to control the microbursting outbound towards the 7200? Derick ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
Re: [j-nsp] MX and microbursting...
I have tuned up buffers and hold-queues on the 7200 and this has drastically reduced the number of dropped packets, but still there is this rx-ring limitation. This is actually a fairly well known issue as I understand it. Is there anything I could do on the MX to control the microbursting outbound towards the 7200? You might be able to do something with Ethernet flow control - I don't remember if the NPE-G2 can send pause frames. However, most likely you have to do shaping on the MX. Shaping can buffer and smooth out bursts. Obviously, to do this it has to *delay* some packets. Steinar Haug, Nethelp consulting, sth...@nethelp.no ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
Re: [j-nsp] MX and microbursting...
I was thinking of just applying a shaping-rate at the port level. As it stands not more than 300m or so could ever pass through this interface (based ultimately on the sum of the interfaces the traffic is routing to at the WAN edge). It turns out actually there is an EX-4200 between the MX and the 7200. So I'm thinking of just applying a port-level shaper on the EX at 400m or 500m. Flow-control is a no go. From: sth...@nethelp.no sth...@nethelp.no To: dwinkwo...@att.net Cc: juniper-nsp@puck.nether.net Sent: Mon, April 11, 2011 1:13:08 PM Subject: Re: [j-nsp] MX and microbursting... I have tuned up buffers and hold-queues on the 7200 and this has drastically reduced the number of dropped packets, but still there is this rx-ring limitation. This is actually a fairly well known issue as I understand it. Is there anything I could do on the MX to control the microbursting outbound towards the 7200? You might be able to do something with Ethernet flow control - I don't remember if the NPE-G2 can send pause frames. However, most likely you have to do shaping on the MX. Shaping can buffer and smooth out bursts. Obviously, to do this it has to *delay* some packets. Steinar Haug, Nethelp consulting, sth...@nethelp.no ___ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
Re: [j-nsp] MX and microbursting...
We've done that. Its the rx-ring on the controller in the NPE-G2. That is not
tunable. A show controller indicates we are basically microbursting 128 or
more
packets at a time (faster than the next cycle to pull packets off the ring).
Increasing the permanent buffers and the hold-queue definitely reduced the
number of dropped packets significantly, but still over the last 8 hours
(business day) I see about 10k drops. Granted, its over 1.2 billion packets.
I
just don't like seeing 10k drops during the business day.
I will apply traffic-shaping as per previous post.
From: Chris Evans chrisccnpsp...@gmail.com
To: sth...@nethelp.no
Cc: juniper-nsp@puck.nether.net
Sent: Mon, April 11, 2011 3:15:59 PM
Subject: Re: [j-nsp] MX and microbursting...
You can adjust buffers on the 7200. It is not an interface parameter tho.
On Apr 11, 2011 2:56 PM, sth...@nethelp.no wrote:
{master}
show configuration class-of-service fragmentation-maps
DO_NOT_FRAG_RT-768
forwarding-class {
RT {
no-fragmentation;
}
BE {
fragment-threshold 768;
}
SG {
fragment-threshold 768;
}
}
Eh? He said GigE. According to
http://www.juniper.net/techpubs/en_US/junos10.0/information-products/topic-collections/config-guide-services/fragmentation-maps-edit-cos.html
fragmentation-maps is for link service IQ interfaces only.
Steinar Haug, Nethelp consulting, sth...@nethelp.no
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