Gabriel, the question is, what does JUNOS "bandwidth-limit 10m" count into this "10m". Only they application payload? L4 header as well? Or even the IP header? If I send UDP traffic with 10Mbps and router policer "bandwidth-limit 10m" drops ~2.5% of this traffic, then I don't find this normal..
regards, martin 2011/4/4 Gabriel Blanchard <[email protected]>: > The policer is dropping packets in order to slow down your connection to > 10mbps. In my opinion this is working perfectly. > > > > On 2011-04-04, at 8:30 AM, "Martin T" <[email protected]> wrote: > >> With such configuration: >> http://img135.imageshack.us/img135/3162/iperftest.png >> >> ..there is still packet loss present: >> >> [root@ ~]# iperf -c 192.168.2.1 -u -fm -t60 -d -b 10m >> ------------------------------------------------------------ >> Server listening on UDP port 5001 >> Receiving 1470 byte datagrams >> UDP buffer size: 0.04 MByte (default) >> ------------------------------------------------------------ >> ------------------------------------------------------------ >> Client connecting to 192.168.2.1, UDP port 5001 >> Sending 1470 byte datagrams >> UDP buffer size: 0.01 MByte (default) >> ------------------------------------------------------------ >> [ 4] local 192.168.1.1 port 59580 connected with 192.168.2.1 port 5001 >> [ 3] local 192.168.1.1 port 5001 connected with 192.168.2.1 port 44050 >> [ ID] Interval Transfer Bandwidth >> [ 4] 0.0-60.0 sec 71.5 MBytes 10.0 Mbits/sec >> [ 4] Sent 51019 datagrams >> [ 3] 0.0-60.0 sec 69.9 MBytes 9.77 Mbits/sec 0.022 ms 1180/51021 (2.3%) >> [ 3] 0.0-60.0 sec 1 datagrams received out-of-order >> [ 4] Server Report: >> [ 4] 0.0-60.0 sec 69.9 MBytes 9.77 Mbits/sec 0.150 ms 1180/51018 (2.3%) >> [ 4] 0.0-60.0 sec 1 datagrams received out-of-order >> [root@ ~]# >> >> >> What should this "filter-specific" do? According to documentation, >> "Filter-specific policers allow you to configure policers and counters >> for a specific filter name. If the filter-specific statement is not >> configured, then the policer defaults to a term-specific policer", but >> it's rather difficult to understand without examples.. >> >> regards, >> martin >> >> >> 2011/4/4 Ben Dale <[email protected]>: >>> Hi Martin, >>> >>> Your policer bandwidth (10Mbps) is being counted on both ingress and egress >>> and will be stacking - try adding: >>> >>> set firewall policer bw-10Mbps filter-specific >>> >>> and you should see the loss go away. >>> >>> Cheers, >>> >>> Ben >>> >>> On 04/04/2011, at 7:41 PM, Martin T wrote: >>> >>>> I made a following setup: >>>> >>>> http://img690.imageshack.us/img690/3162/iperftest.png >>>> >>>> In a laptop, an Iperf server is listening like this: "iperf -s -u -fm". >>>> In a workstation, an Iperf client is executed like this: "iperf -c >>>> 192.168.2.1 -u -fm -t60 -d -b 10m". This will execute simultaneous >>>> 10Mbps UDP traffic flood between 192.168.1.1 and 192.168.2.1 for 1 >>>> minute. Results are always like this: >>>> >>>> [root@ ~]# iperf -c 192.168.2.1 -u -fm -t60 -d -b 10m >>>> ------------------------------------------------------------ >>>> Server listening on UDP port 5001 >>>> Receiving 1470 byte datagrams >>>> UDP buffer size: 0.04 MByte (default) >>>> ------------------------------------------------------------ >>>> ------------------------------------------------------------ >>>> Client connecting to 192.168.2.1, UDP port 5001 >>>> Sending 1470 byte datagrams >>>> UDP buffer size: 0.01 MByte (default) >>>> ------------------------------------------------------------ >>>> [ 4] local 192.168.1.1 port 32284 connected with 192.168.2.1 port 5001 >>>> [ 3] local 192.168.1.1 port 5001 connected with 192.168.2.1 port 52428 >>>> [ ID] Interval Transfer Bandwidth >>>> [ 4] 0.0-60.0 sec 71.5 MBytes 10.0 Mbits/sec >>>> [ 4] Sent 51021 datagrams >>>> [ 4] Server Report: >>>> [ 4] 0.0-59.9 sec 69.8 MBytes 9.77 Mbits/sec 0.112 ms 1259/51020 >>>> (2.5%) >>>> [ 4] 0.0-59.9 sec 1 datagrams received out-of-order >>>> [ 3] 0.0-60.0 sec 69.8 MBytes 9.77 Mbits/sec 0.030 ms 1200/51021 >>>> (2.4%) >>>> [ 3] 0.0-60.0 sec 1 datagrams received out-of-order >>>> [root@ ~]# >>>> >>>> As you can see, there is a ~2.5% packet loss. This packet loss is due >>>> to the fact, that router "bw-10Mbps" policer drops small percentage of >>>> packages in "input" direction(I can check the amount of dropped >>>> packets with "show policer" command). For example if I increase the >>>> policer "bandwidth-limit" to "11m", there will be no packet loss. >>>> >>>> In both machines(192.168.1.1 and 192.168.2.1) Iperf sends packets with >>>> 1470 byte payload. In addition, there is a 8 byte UDP header and 20 >>>> byte IPv4 header. So according to tcpdump the whole IPv4 packet is >>>> 1498 bytes: >>>> >>>> >>>> [root@ ~]# tcpdump -i fxp0 -c 4 -v >>>> tcpdump: listening on fxp0, link-type EN10MB (Ethernet), capture size 96 >>>> bytes >>>> 11:49:18.961405 IP (tos 0x0, ttl 63, id 44836, offset 0, flags [DF], >>>> proto UDP (17), length 1498) >>>> 192.168.2.1.52428 > 192.168.1.1.commplex-link: UDP, length 1470 >>>> 11:49:18.961459 IP (tos 0x0, ttl 64, id 37052, offset 0, flags [none], >>>> proto UDP (17), length 1498) >>>> 192.168.1.1.32284 > 192.168.2.1.commplex-link: UDP, length 1470 >>>> 11:49:18.961473 IP (tos 0x0, ttl 64, id 37053, offset 0, flags [none], >>>> proto UDP (17), length 1498) >>>> 192.168.1.1.32284 > 192.168.2.1.commplex-link: UDP, length 1470 >>>> 11:49:18.961485 IP (tos 0x0, ttl 64, id 37054, offset 0, flags [none], >>>> proto UDP (17), length 1498) >>>> 192.168.1.1.32284 > 192.168.2.1.commplex-link: UDP, length 1470 >>>> 4 packets captured >>>> 284 packets received by filter >>>> 0 packets dropped by kernel >>>> [root@ ~]# >>>> >>>> Whole frame size is 1512 bytes. >>>> >>>> Does JUNOS include UDP(or L3 header in general) header to this >>>> "bandwidth-limit 10m"? If it does, shouldn't there be 0.5% packet loss >>>> instead of 2.5%? Or if "bandwidth-limit 10m" includes IPv4 header as >>>> well, the packet loss for Iperf should be >>>> >>>> 1498 - 100% >>>> 28 - x% >>>> >>>> ..1.9% not ~2.5%. Are my calculations wrong or how does JUNOS policer >>>> "bandwidth-limit" calculate this 10m bits? >>>> >>>> >>>> regards, >>>> martin >>>> _______________________________________________ >>>> juniper-nsp mailing list [email protected] >>>> https://puck.nether.net/mailman/listinfo/juniper-nsp >>>> >>> >>> >> >> _______________________________________________ >> juniper-nsp mailing list [email protected] >> https://puck.nether.net/mailman/listinfo/juniper-nsp > _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
