Wireshark mailing list archives
Re: Traffic problems under Window 2008
From: Martin Visser <martinvisser99 () gmail com>
Date: Mon, 31 May 2010 14:22:24 +1000
Switches do not hold onto packets for 4 seconds. They either forward them within milliseconds or drop them in the event of congestion. (They may have queues but they would not extend to more than a few megabytes of packets, and hence are very quickly emptied into the output interface - you would have evidence of congestion (fully saturated bandwidth) on the ingress or egress interface if this were occuring). I would interpret those delays as there being nothing for the client to send, or it is waiting for some ACKnowledgement from the other end, or a timer (for say a unanswered DNS or name lookup) has expired. It is possible that the first was sent but because of errors was dropped silently. If you are getting packet loss because of errors, this would show up in the device port statistics. Duplex issues can cause similar problems, but not likely to see seconds of delay. Also you would expect to see collision errors on the interface configured as half-duplex if that is the case (usually also best seen in the port statistics on the device). The fact that 172.18.100.18 is doing a Netbios Name Service broadcast query for a loopback (127.0.0.1) based service already worries me that you have a misconfiguration or non-answering name service. So you may have an application or OS config issue. Regards, Martin MartinVisser99 () gmail com On Fri, May 28, 2010 at 1:26 AM, Eddie Grogan <eddiegrogan () googlemail com>wrote:
Hello, I am running traffic between a Windows 2008 server and switch (via a router). While traffic will run perfectly for days, we occasionally see small delays on the network which bring down our software. Typically, we might see a couple of blockages of aprox 5 seconds in duration. We have only starting seeing these problems since we moved to Windows 2008. On Window 2003, everything worked perfectly. Now, I am not sure if this is a problem with the OS or perhaps some type of OS incompatibility issue with our hardware. Here is a quick snippet of where things start to wrong in our logs. 16223 0.000456 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [PSH, ACK] Seq=535013 Ack=4164690 Win=253 Len=64616224 0.099948 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [ACK] Seq=4164690 Ack=535659 Win=16738 Len=0 16225 1.179883 172.18.100.15 172.18.100.18 ICMP Echo (ping) request 16226 0.000709 172.18.100.18 172.18.100.15 ICMP Echo (ping) reply 16227 3.052179 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [PSH, ACK] Seq=4164690 Ack=535659 Win=16738 Len=492 16228 0.019502 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [PSH, ACK] Seq=535659 Ack=4165182 Win=251 Len=3216229 0.047537 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [ACK] Seq=4165182 Ack=535691 Win=16706 Len=0 16230 0.000332 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [PSH, ACK] Seq=535691 Ack=4165182 Win=251 Len=6416231 0.099530 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [ACK] Seq=4165182 Ack=535755 Win=16642 Len=0 16232 1.393205 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [PSH, ACK] Seq=535755 Ack=4165182 Win=251 Len=3416233 0.006954 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [ACK] Seq=4165182 Ack=535789 Win=16608 Len=0 Note: Our switch will ping the server every 6 seconds. In general, we would not expect to see any communication delays between then switch and the server. The max response time is aprox 300ms but generally response time is much lower. But at frame *16227*, we see that it takes almost 4.2 seconds (3.05 + 1.17) for the switch to send out the next packet. I think this is interesting because in between the switch was able to ping the server without any delays which suggests to me that the network is still healthy. At frame *16232*, we see that the server takes 1.4 seconds to respond to the previous packet (i.e. ACK). A little later in the logs, we see even more delays, only this time they are all originating on the switch side: 16293 0.099612 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [ACK] Seq=4208432 Ack=535915 Win=17491 Len=0 16294 0.379674 172.18.100.15 172.18.100.18 ICMP Echo (ping) request 16295 0.000428 172.18.100.18 172.18.100.15 ICMP Echo (ping) reply *16296 3.733783 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [PSH, ACK] Seq=4208432 Ack=535915 Win=17520 Len=495* - 16297 0.200446 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [ACK] Seq=535915 Ack=4208927 Win=254 Len=016298 0.205381 172.18.100.18 224.0.0.252 IGMP V2 Membership Report / Join group 224.0.0.252 16299 0.473254 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [PSH, ACK] Seq=535915 Ack=4208927 Win=254 Len=2116300 0.006626 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [ACK] Seq=4208927 Ack=535936 Win=17520 Len=0 16301 1.380183 172.18.100.15 172.18.100.18 ICMP Echo (ping) request 16302 0.000726 172.18.100.18 172.18.100.15 ICMP Echo (ping) reply 16303 1.855978 172.18.100.18 172.18.100.255 NBNS Name query NB 127.0.0.1,4001<00> 16304 0.206693 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [PSH, ACK] Seq=4208927 Ack=535936 Win=17520 Len=510 16305 0.200422 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [ACK] Seq=535936 Ack=4209437 Win=252 Len=016306 0.342543 172.18.100.18 172.18.100.255 NBNS Name query NB 127.0.0.1,4001<00> 16307 0.750224 172.18.100.18 172.18.100.255 NBNS Name query NB 127.0.0.1,4001<00> 16308 0.283679 172.18.100.18 224.9.9.2 IGMP V2 Membership Report / Join group 224.9.9.2 16309 0.467106 172.18.100.18 172.18.100.255 NBNS Name query NB 127.0.0.1,4001<00> 16310 0.749850 172.18.100.18 172.18.100.255 NBNS Name query NB 127.0.0.1,4001<00> 16311 0.750133 172.18.100.18 172.18.100.255 NBNS Name query NB 127.0.0.1,4001<00> 16312 0.392744 172.18.100.15 172.18.100.18 ICMP Echo (ping) request 16313 0.000770 172.18.100.18 172.18.100.15 ICMP Echo (ping) reply *16314 2.094337 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [PSH, ACK] Seq=4209437 Ack=535936 Win=17520 Len=510* 16315 0.200015 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [ACK] Seq=535936 Ack=4209947 Win=256 Len=016316 3.704503 172.18.100.15 172.18.100.18 ICMP Echo (ping) request 16317 0.000520 172.18.100.18 172.18.100.15 ICMP Echo (ping) reply *16318 3.777418 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [PSH, ACK] Seq=4209947 Ack=535936 Win=17520 Len=510* 16319 0.209945 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [ACK] Seq=535936 Ack=4210457 Win=254 Len=016320 2.012220 172.18.100.15 172.18.100.18 ICMP Echo (ping) request 16321 0.000599 172.18.100.18 172.18.100.15 ICMP Echo (ping) reply *16322 5.740877 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [PSH, ACK] Seq=4210457 Ack=535936 Win=17520 Len=510* 16323 0.203816 172.18.100.18 172.18.100.15 TCP 49235ddi-tcp-1 [ACK] Seq=535936 Ack=4210967 Win=252 Len=016324 0.054286 172.18.100.15 172.18.100.18 ICMP Echo (ping) request 16325 0.000921 172.18.100.18 172.18.100.15 ICMP Echo (ping) reply *16326 5.611319 172.18.100.18 172.18.100.15 TCP 49235 > ddi-tcp-1 [PSH, ACK] Seq=535936 Ack=4210967 Win=252 Len=21* 16327 0.007736 172.18.100.15 172.18.100.18 TCP ddi-tcp-1 > 49235 [ACK] Seq=4210967 Ack=535957 Win=17520 Len=0 When we look at the first delay at frame *16296*, we see a 4 second time lag to the previous data frame (i.e. *16293*). The subsequent blockages have even larger delays - Frames *16314* (5.7sec), *16318* (7.4 sec), * 16322* (7.7 sec) and *16326* (5.6 sec). All of these delays are originating on the switch side. I don’t see any real delays on the server side responding to the data packets or the ping requests. The above traces also show that there was other activity on the network. I can see a lot of *NetBios* and *Router* activity at this time but I don’t know if this is impacting. Looking at the rest of the sniffer logs I can see a large number of malformed packets. Here is a typically example *4774 0.000113 172.18.100.15 172.18.100.18 UCP Roaming reset (Result) [checksum invalid][Malformed Packet]* In all cases, the malformed packets originated from the switch. Again, I am not sure how significant this is. I would be grateful if anyone could provide any insight into the above. Thanks Eddie ___________________________________________________________________________ Sent via: Wireshark-users mailing list <wireshark-users () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-users Unsubscribe: https://wireshark.org/mailman/options/wireshark-users mailto:wireshark-users-request () wireshark org ?subject=unsubscribe
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Current thread:
- Traffic problems under Window 2008 Eddie Grogan (May 28)
- Re: Traffic problems under Window 2008 dan meyer (May 28)
- Re: Traffic problems under Window 2008 Martin Visser (May 30)
- Re: Traffic problems under Window 2008 kevin creason (May 31)