nanog mailing list archives
Re: Linux Router: TCP slow, UDP fast
From: Nickola Kolev <nikky () mnet bg>
Date: Sat, 14 Feb 2009 16:18:54 +0200
Hello, Chris, So, as it seems you have problem with TCP, and not UDP, maybe this is something with regard to TCP segmentation offloading. It could be a total shot in the dark, but can you see what ethtool -k <devname> says? Then you can have a look at 'man ethtool' and turn on/off the appropriate stuff. On Sat, 14 Feb 2009 13:48:53 +0000 Chris <chris () ghostbusters co uk> wrote:
Thanks loads for the quick replies. I'll try and respond individually. Lee > I recently disabled tcp_window_scaling and it didn't solve the problem. I don't know enough about it. Should I enable it again ? Settings differing from defaults are copied in my first post. Mike > Strangely I'm not seeing any errors on either the ingress or egress NICs: RX packets:3371200609 errors:0 dropped:0 overruns:0 frame:0 TX packets:3412500706 errors:0 dropped:0 overruns:0 carrier:0 The only errors I see anywhere are similar on both NICs. Both connect to the same model of switch with the same default config: rx_long_byte_count: 1396158525465 rx_csum_offload_good: 3341342496 rx_csum_offload_errors: 89459 and it may be worth noting that flow control is on. Are these a reasonable level of pause frames to be seeing ? They seem to be higher on non-routing boxes. Total bytes (TX)2466202288Unicast packets (TX)3436389971Multicast packets (TX)213310Broadcast packets (TX)4952902Single Collision Frames (TX)0Late Collisions (TX)0Excessive Collisions (TX)0Transmitted Pause Frames (TX)27806 Florian > They're running without obvious errors. Auto Neg has taken 1Gbps, Full. Can Auto Neg cause these symptoms do you think ? Thanks again, Chris
-- Best regards, Nickola
Current thread:
- Linux Router: TCP slow, UDP fast Chris (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Lee (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Mikael Abrahamsson (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Florian Weimer (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Chris (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Nickola Kolev (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Chris (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Lee (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Chris (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Lee (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Chris (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Chris (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Mikael Abrahamsson (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Chris (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Lee (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Florian Weimer (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Chris (Feb 14)
- Re: Linux Router: TCP slow, UDP fast Chris (Feb 14)