[c-nsp] high cpu usage because of process switching on mlppp interface
Arda Balkanay
ardabalkanay at gmail.com
Tue Sep 4 15:19:21 EDT 2007
Thank you Rodney,
i will check my configs again and share the results with you.
On 9/4/07, Rodney Dunn <rodunn at cisco.com> wrote:
>
> I'd like to see the full config of the 72xx.
>
> Also, can you do the following:
>
> a) disable fragmentation on both sides "no ppp multilink fragmentation"
> b) remove all non MLPPP commands from the member links of the bundle
> You should add those to the MLPPP interface itself
>
> You are process switcing all of your traffic inbound on the MLPPP
> interface of the 72xx:
>
> > > MTP-C72-02#sh inter mul 1 switching
> > > Multilink1 Maltepe - Adana MLPPP
> > > Throttle count 0
> > > Drops RP 752707
> SP 0
> > > SPD Flushes
> Fast 0 SSE 0
> > > SPD Aggress Fast 0
> > > SPD Priority
> Inputs 259 Drops 0
> > >
> > > Protocol IP
> > > Switching path Pkts In Chars In Pkts Out Chars
> Out
> > > Process 50148189 395174672 261949
> 26235771
> > > Cache
> misses 0 - - -
> > > Fast 1325 105874 12194
> 724886
> >
> > Auton/SSE 0 0 0 0
> > >
> > > Protocol Tag
> > > Switching path Pkts In Chars In Pkts Out Chars
> Out
> > > Process 79390997 3601460527 5116
> 538398
> > > Cache
> misses 0 - - -
> > > Fast 0 0 87354606
> 4071850482
> >
> > Auton/SSE 0 0 0 0
>
>
> so that tells me it's another feature configured most likely on the egress
> interface this traffic will go out of or a bad bug.
>
> Notice it's doing it for both ingress ip and MPLS.
>
>
> Rodney
>
>
> On Mon, Sep 03, 2007 at 08:47:04AM +0300, Arda Balkanay wrote:
> > Hi
> > I haven't had a TAC SR yet about this issue, and i couldn't find the
> related
> > topic previously covered
> > in this group so sory for double opening of this kind of subject.
> > In my scenario i am running mpls over mlppp. this line is my pop uplink.
> > I could'nt get useful information about my problem from the command
> "show cef
> > interface" output.
> > According to your previous mail can you please send me the Bug ID, on
> the other
> > hand i can open a TAC case
> > for this issue, but before i should study cisco switching architecture
> (like
> > process switching fast switching and so on)
> >
> >
> > MTP-C72-02#sh cef interface mu 1
> > Multilink1 is up (if_number 55)
> > Corresponding hwidb fast_if_number 55
> > Corresponding hwidb firstsw->if_number 55
> > Internet address is 85.29.8.101/30
> > ICMP redirects are always sent
> > Per packet load-sharing is disabled
> > IP unicast RPF check is disabled
> > Inbound access list is not set
> > Outbound access list is not set
> > Interface is marked as point to point interface
> > Hardware idb is Multilink1
> > Fast switching type 7, interface type 94
> > IP CEF switching enabled
> > IP CEF Fast switching turbo vector
> > IP Null turbo vector
> > Input fast flags 0x0, Input fast flags2 0x0, Output fast flags 0x0,
> Output
> > fast flags2 0x0
> > ifindex 31(31)
> > Slot -1 Slot unit 1 Unit 1 VC -1
> > Transmit limit accumulator 0x0 (0x0)
> > IP MTU 1500
> >
> > ADN-C38-01#sh cef interface Mu1
> > Multilink1 is up (if_number 21)
> > Corresponding hwidb fast_if_number 21
> > Corresponding hwidb firstsw->if_number 21
> > Internet address is 85.29.8.102/30
> > ICMP redirects are always sent
> > Per packet load-sharing is disabled
> > IP unicast RPF check is disabled
> > Inbound access list is not set
> > Outbound access list is not set
> > Interface is marked as point to point interface
> > Hardware idb is Multilink1
> > Fast switching type 7, interface type 94
> > IP CEF switching enabled
> > IP CEF Fast switching turbo vector
> > Input fast flags 0x0, Input fast flags2 0x0, Output fast flags 0x0,
> Output
> > fast flags2 0x0
> > ifindex 17(17)
> > Slot -1 Slot unit 1 Unit 1 VC -1
> > Transmit limit accumulator 0x0 (0x0)
> > IP MTU 1500
> > ADN-C38-01#
> >
> >
> > My interface configs are as follow:
> >
> > MTP-C72-02#sh run int mu 1
> > Building configuration...
> >
> > Current configuration : 262 bytes
> > !
> > interface Multilink1
> > description Maltepe - Adana MLPPP
> > mtu 1600
> > ip address 85.29.8.101 255.255.255.252
> > ip mtu 1500
> > mpls label protocol ldp
> > tag-switching mtu 1524
> > tag-switching ip
> > ppp multilink
> > ppp multilink group 1
> > ppp multilink mrru local 1604
> > end
> >
> > MTP-C72-02#sh ppp mu
> >
> > Multilink1, bundle name is ADN-C38-01
> > Endpoint discriminator is ADN-C38-01
> > Bundle up for 2d01h, 174/255 load
> > Receive buffer limit 25664 bytes, frag timeout 1000 ms
> > 0/0 fragments/bytes in reassembly list
> > 16890 lost fragments, 357474026 reordered
> > 7820/896328 discarded fragments/bytes, 0 lost received
> > 0xD2B4CA received sequence, 0x8EC33D sent sequence
> > Member links: 2 active, 0 inactive (max not set, min not set)
> > Se4/0:0, since 2d01h
> > Se2/3:0, since 2d01h
> > No inactive multilink interfaces
> >
> > MTP-C72-02#sh run int ser 4/0:0
> > Building configuration...
> >
> > Current configuration : 258 bytes
> > !
> > interface Serial4/0:0
> > description Tellcom 2Maltepe-Adana 2Mbps LL DATA NO:0107110068
> > mtu 1600
> > no ip address
> > ip mtu 1500
> > encapsulation ppp
> > load-interval 30
> > mpls label protocol ldp
> > tag-switching mtu 1524
> > tag-switching ip
> > ppp multilink group 1
> > end
> >
> > MTP-C72-02#sh run int ser 2/3:0
> > Building configuration...
> >
> > Current configuration : 264 bytes
> > !
> > interface Serial2/3:0
> > description Tellcom Maltepe-Adana 2Mbps LL DATA NO:0107110060
> > mtu 1600
> > no ip address
> > encapsulation ppp
> > load-interval 30
> > mpls label protocol ldp
> > tag-switching mtu 1524
> > tag-switching ip
> > fair-queue 64 16 0
> > ppp multilink group 1
> > end
> > MTP-C72-02#sh run int ser 4/0:0
> > Building configuration...
> >
> > Current configuration : 258 bytes
> > !
> > interface Serial4/0:0
> > description Tellcom 2Maltepe-Adana 2Mbps LL DATA NO:0107110068
> > mtu 1600
> > no ip address
> > ip mtu 1500
> > encapsulation ppp
> > load-interval 30
> > mpls label protocol ldp
> > tag-switching mtu 1524
> > tag-switching ip
> > ppp multilink group 1
> > end
> >
> > MTP-C72-02#sh run int ser 2/3:0
> > Building configuration...
> >
> > Current configuration : 264 bytes
> > !
> > interface Serial2/3:0
> > description Tellcom Maltepe-Adana 2Mbps LL DATA NO:0107110060
> > mtu 1600
> > no ip address
> > encapsulation ppp
> > load-interval 30
> > mpls label protocol ldp
> > tag-switching mtu 1524
> > tag-switching ip
> > fair-queue 64 16 0
> > ppp multilink group 1
> > end
> >
> >
> > ADN-C38-01#sh run int mu 1
> > Building configuration...
> >
> > Current configuration : 244 bytes
> > !
> > interface Multilink1
> > description Adana - Maltepe MLPPP
> > mtu 1600
> > ip address 85.29.8.102 255.255.255.252
> > ip mtu 1500
> > mpls label protocol ldp
> > mpls ip
> > mpls mtu 1524
> > ppp multilink
> > ppp multilink group 1
> > ppp multilink mrru local 1604
> > end
> >
> > ADN-C38-01#sh ppp mu
> >
> > Multilink1, bundle name is MTP-C72-02
> > Endpoint discriminator is MTP-C72-02
> > Bundle up for 2d01h, total bandwidth 4096, load 186/255
> > Receive buffer limit 25664 bytes, frag timeout 1000 ms
> > 0/0 fragments/bytes in reassembly list
> > 42246 lost fragments, 185970460 reordered
> > 35687/1919036 discarded fragments/bytes, 0 lost received
> > 0x9256EA received sequence, 0xD6C17F sent sequence
> > Member links: 2 active, 0 inactive (max not set, min not set)
> > Se0/0/1:0, since 2d01h
> > Se0/0/0:0, since 2d01h
> > No inactive multilink interfaces
> > ADN-C38-01#sh run int ser 0/0/0:0
> > Building configuration...
> >
> > Current configuration : 241 bytes
> > !
> > interface Serial0/0/0:0
> > description Tellcom Adana-Maltepe 2Mbps LL DATA NO:0107110060
> > mtu 1600
> > no ip address
> > ip mtu 1500
> > encapsulation ppp
> > load-interval 30
> > mpls label protocol ldp
> > mpls ip
> > mpls mtu 1524
> > ppp multilink group 1
> > end
> >
> > ADN-C38-01#sh run int ser 0/0/1:0
> > Building configuration...
> >
> > Current configuration : 265 bytes
> > !
> > interface Serial0/0/1:0
> > description Tellcom 2Adana-Maltepe 2Mbps LL DATA NO:0107110068
> > mtu 1600
> > no ip address
> > ip mtu 1500
> > encapsulation ppp
> > no ip route-cache cef
> > load-interval 30
> > mpls label protocol ldp
> > mpls ip
> > mpls mtu 1524
> > ppp multilink group 1
> > end
> >
> > Thanks for your help
> > Kind Regards
> > Arda
> >
> > On 8/29/07, Rodney Dunn <rodunn at cisco.com> wrote:
> >
> > Do you have a TAC SR open on this?
> >
> > I just saw someone ask this a few days ago and I told them it's
> > a bug.
> >
> > We support CEF switching of data over a MLPPP bundle with
> > MPLS.
> >
> >
> > Are you running MPLSoMLPPP or are you just running the MLPPP
> > interface in a VRF?
> >
> > > MTP-C72-02#sh inter mul 1 switching
> > > Multilink1 Maltepe - Adana MLPPP
> > > Throttle count 0
> > > Drops RP 752707
> SP 0
> > > SPD Flushes
> Fast 0 SSE 0
> > > SPD Aggress Fast 0
> > > SPD Priority
> Inputs 259 Drops 0
> > >
> > > Protocol IP
> > > Switching path Pkts In Chars In Pkts Out Chars
> Out
> > > Process 50148189 395174672 261949
> 26235771
> > > Cache
> misses 0 - - -
> > > Fast 1325 105874 12194
> 724886
> >
> > Auton/SSE 0 0 0 0
> > >
> > > Protocol Tag
> > > Switching path Pkts In Chars In Pkts Out Chars
> Out
> > > Process 79390997 3601460527 5116
> 538398
> > > Cache
> misses 0 - - -
> > > Fast 0 0 87354606
> 4071850482
> >
> > Auton/SSE 0 0 0 0
> >
> >
> > shows you are process switching a ton of your IP traffic and all
> > of the inbound MPLS traffic.
> >
> > Outbound your mpls traffic is fine so we need to look at the inbound
> > switching vectors coming in the MLPPP interface.
> >
> > As Bruce said can you get 'sh cef in mu 1'?
> >
> > Also, post the configs of the mlppp interface as well as the other
> > interfaces this traffic will go out of once it comes in the MLPPP
> > interface?
> >
> > Rodney
> >
> >
> >
> >
> > On Wed, Aug 29, 2007 at 03:15:19PM +0300, Arda Balkanay wrote:
> > > Hi
> > > i have a problem about high cpu usage on a 7206 VXR NPE-G1 because
> of
> > > process switching on a multilink ppp interface.
> > >
> > > I have two E1 interfaces between 7206 and 3845 (below MTP-C72-02
> > indicates
> > > 7206 and ADN-C38-01 indicates 3845).
> > > I've bundled these two E1 interfaces. And when the amount of
> traffic
> > rised
> > > CPU usage also increased about 15 percent more.
> > > "show proc cpu" output points increase at the processes of ip
> input and
> > tag
> > > input.
> > > MTP-C72-02#sh proc cpu sorted
> > > CPU utilization for five seconds: 78%/64%; one minute: 79%; five
> minutes:
> > > 81%
> > > PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY
> Process
> > > 68 39242000 258183793 151 8.92% 8.20% 8.40% 0 IP
> > > Input
> > > 109 25093708 119681214 209 6.88% 7.37% 7.79% 0
> Tag Input
> > >
> > >
> > > When i looked at the switching status of the interface i saw that
> 7206 is
> > > using process switching while 3845 uses fast switchig (especially
> for
> > mpls)
> > > MTP-C72-02#sh inter mul 1 switching
> > > Multilink1 Maltepe - Adana MLPPP
> > > Throttle count 0
> > > Drops RP 752707
> SP 0
> > > SPD Flushes
> Fast 0 SSE 0
> > > SPD Aggress Fast 0
> > > SPD Priority
> Inputs 259 Drops 0
> > >
> > > Protocol IP
> > > Switching path Pkts In Chars In Pkts Out Chars
> Out
> > > Process 50148189 395174672 261949
> 26235771
> > > Cache
> misses 0 - - -
> > > Fast 1325 105874 12194
> 724886
> >
> > Auton/SSE 0 0 0 0
> > >
> > > Protocol Tag
> > > Switching path Pkts In Chars In Pkts Out Chars
> Out
> > > Process 79390997 3601460527 5116
> 538398
> > > Cache
> misses 0 - - -
> > > Fast 0 0 87354606
> 4071850482
> >
> > Auton/SSE 0 0 0 0
> > >
> > >
> > > ADN-C38-01#sh inter mu 1 switching
> > > Multilink1 Adana - Maltepe MLPPP
> > > Throttle count 0
> > > Drops RP 0
> SP 0
> > > SPD Flushes
> Fast 0 SSE 0
> > > SPD Aggress Fast 0
> > > SPD Priority
> Inputs 242 Drops 0
> > >
> > > Protocol IP
> > > Switching path Pkts In Chars In Pkts Out Chars
> Out
> >
> > Process 32394 2110804 17595 1260300
> > > Cache
> misses 0 - - -
> > > Fast 559376 60411948 154
> 8439
> >
> > Auton/SSE 0 0 0 0
> > >
> > > Protocol Tag
> > > Switching path Pkts In Chars In Pkts Out Chars
> Out
> > > Process 7106 398899 10784
> 539203
> > > Cache
> misses 0 - - -
> > > Fast 87130476 3140243335
> 80454345 488241675
> >
> > Auton/SSE 0 0 0 0
> > >
> > >
> > > When i checked "show ip interface" output i can see that fast
> swithing is
> > > enabled but i didn't understand why 7206 uses process switching
> while
> > 3845
> > > uses fast
> > > swithcing with the same multilink interface configuration. ip
> interface
> > > output is as follows:
> > >
> > > MTP-C72-02#sh ip int mu 1
> > > Multilink1 is up, line protocol is up
> > > ...
> > > IP fast switching is enabled
> > > IP fast switching on the same interface is enabled
> > > IP Flow switching is disabled
> > > IP CEF switching is enabled
> > > IP CEF Fast switching turbo vector
> > > IP Null turbo vector
> > > IP multicast fast switching is enabled
> > > IP multicast distributed fast switching is disabled
> > > IP route-cache flags are Fast, CEF
> > > ...
> > > MTP-C72-02#
> > >
> > > ADN-C38-01#sh ip int mu 1
> > > Multilink1 is up, line protocol is up
> > > ...
> > > IP fast switching is enabled
> > > IP fast switching on the same interface is enabled
> > > IP Flow switching is disabled
> > > IP CEF switching is enabled
> > > IP CEF Fast switching turbo vector
> > > IP multicast fast switching is enabled
> > > IP multicast distributed fast switching is disabled
> > > IP route-cache flags are Fast, CEF
> > > ...
> > > ADN-C38-01#
> > > 7206 uses ios c7200-jk9s-mz.123-14.T3.bin and 3845 uses
> > > c3845-spservicesk9-mz.124-8b.bin
> > >
> > >
> > > Do you have any idea about this situation ?
> > >
> > >
> > > Kind Regards
> > > Arda
> > > _______________________________________________
> > > cisco-nsp mailing list cisco-nsp at puck.nether.net
> > > https://puck.nether.net/mailman/listinfo/cisco-nsp
> > > archive at http://puck.nether.net/pipermail/cisco-nsp/
> >
> >
>
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