[c-nsp] Problem with dscp packets marking on 76th platform.

Nicolás Leiva nicolasleiva at gmail.com
Wed Nov 25 11:46:10 EST 2009


You might want to review
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/mplsqos.html#wp1509501
.

Nicolas

On Wed, Nov 25, 2009 at 12:51 PM, Teslenko <ex_art at mail.ru> wrote:

> selamat pagi пишет:
> > What's the config on the ingress interface of PE1 ?
> > Do you use VPNs (vrf interface) ?
> > Is TE active ?
>
> I have understood that it has misled you
>
> >>>> ping from CE
> >>>>      Type escape sequence to abort.
> >>>>      Sending 100, 100-byte ICMP Echos to 10.10.10.5, timeout is 2
> >> seconds:
> >>>>      Packet sent with a source address of 10.10.10.1
>
>
> Really initially the traffic ran between two vrf
> The scheme of traffic's movement looks as  follows
>
> [SW-1]--1->(Te1.661)PE1(Te1.662)--2->[SW-1]--3->(Gi0/1)PE2
>
> This test was necessary to understand "Does marking work in general?"
>
> Yes, it does.
>
> Then was tested MPLS scheme with P router and without P
>
> First. With P router
>
> [SW-1]--> (Te1.661)PE1--(/30,MPLS/OSPF)--> P--(/30,MPLS/OSPF)--> PE2
> -->(82.xx.xx.160/30)->CE
>
> So we saw  marking do not occur
> When we use the scheme without router P all works correctly
>
> [SW-1]--> (Te1.661)PE1--(/30,MPLS/OSPF)--> PE2 -->(82.xx.xx.160/30)->CE
>
> But a problem not in  P router.
> It has been stated in previous letter
> Problem occur when MPLS label is encapsulating to header of packets.
> This doesn't occur when P not present in scheme,
> because PE1 became penultimate for PE2.
> So MPLS label doesn't change, because PHP is enable on PE2 by default.
>
>
> Interface configuration between SW-1 and PE1 looks as follow
> ==================================================
> [SW-1]--1->(Te1.661)PE1
> ==================================================
> ------------------ listing -----------------------
> 1) SW-1:
> interface Vlan661
>  ip address 62.xxx.xx.20 255.255.255.240
> End
> ip route 82.xx.xx.161 255.255.255.255 62.xxx.xx.17
>
> 2) PE1:
> interface Te1.661
>  encapsulation dot1Q 661
>  ip address 62.xxx.xx.17 255.255.255.240
>  no ip redirects
>  no ip proxy-arp
>  ip mtu 1500
>  service-policy input test-in-dscp-set
> end
>
>  PE1#sh policy-map test-in-dscp-set
>  Policy Map test-in-dscp-set
>    Class test
>      set ip dscp 39
>    Class class-default
>
>  PE1#sh class-map test
>  Class Map match-all test (id 25)
>   Match access-group  100
>
> PE1#sh run | i access-list 100
> access-list 100 permit ip host 62.xxx.xx.20 host 82.xx.xx.161
> access-list 100 deny   ip any any
> ----------------- end of listing----------------
>
>
> Interface configuration on PE2
> =================================================
>  PE2 -->(82.xx.xx.160/30)->CE
> =================================================
> ------------------ listing -----------------------
> interface Gi1.205
>  encapsulation dot1Q 205
>  ip address 82.xx.xx.162 255.255.255.252
>  no ip redirects
>  no ip proxy-arp
>  ip mtu 1500
>  ip flow ingress
>  no cdp enable
>  service-policy output test-Out
> end
>
>  PE2#sh policy-map test-Out
>  Policy Map test-Out
>    Class test
>    Class class-default
>
>  PE2#sh class-map test
>  Class Map match-all test (id 27)
>   Match ip  dscp 39
> ----------------- end of listing----------------
>
> ===============================================
> Start Test
> ===============================================
> ------------------ listing -----------------------
> SW-1#ping 82.xx.xx.161 source 62.xx.xx.20 repeat 10
>
> PE1#sh policy-map interface Te1.661
>  TenGigabitEthernet1.661
>  Service-policy input: test
>    class-map: test (match-all)
>      Match: access-group 100
>      set dscp 39:
>      Earl in slot 1 :
>        1180 bytes
>        30 second offered rate 280 bps
>        aggregate-forwarded 1180 bytes
>    Class-map: class-default (match-any)
>      0 packets, 0 bytes
>      30 second offered rate 0 bps, drop rate 0 bps
>      Match: any
>        0 packets, 0 bytes
>        30 second rate 0 bps
>
> PE2# sh policy-map interface Gi1.205 output class test
>  GigabitEthernet1.205
>  Service-policy output: test-Out
>    Class-map: test (match-all)
>      0 packets, 0 bytes
>      30 second offered rate 0 bps
>      Match: ip dscp 39
> ----------------- end of listing----------------
>
>
>
> > cheers, ketimun
> >
> >
> > On Wed, Nov 25, 2009 at 12:09 PM, Teslenko <ex_art at mail.ru> wrote:
> >
> >> Hello All,
> >>
> >> We try to introduce Qos in ours IP/MPLS backbone network,
> >> constructed on routers 7600th series
> >>
> >> All 76-s' are P or PE devices should accept from outside  MPLS or IP
> >> traffic.
> >> On PE devices we mark packages and we want, that DSCP was transferred
> >> transparently within MPLS domain. But we have problem.
> >>
> >> We use IOS  v12.2 (33) SRC1 now.
> >>
> >>
> >> Testing passed on CISCO7609-S with linear card WS-X6708-10GE
> >>
> >>
> >> ==================================
> >>                                      The test #1
> >> ==================================
> >>
> >> P device CISCO7609-S ingress port on linear card WS-X6708-10GE,
> >> egress port on linear card WS-X6724-SFP.
> >> Device PE2 the last in a chain, PHP option enable  by default
> >>
> >>  The scheme of traffic's movement looks as  follows
> >>
> >>  CE--> SW-1> (ingress) PE1 (egress)--> P--> (ingress) PE2
> >>
> >> 1.1 Interfaces  of the P  device are configured as follows
> >>
> >> interface TenGigabitEthernet (WS-X6708-10GE)
> >>  dampening
> >>  mtu 4470
> >>  ip address yy.yy.yy.yy 255.255.255.252
> >>  carrier-delay msec 0
> >>  mpls traffic-eng tunnels
> >>  mpls ip
> >>  hold-queue 1000 in
> >>  ip rsvp bandwidth
> >> end
> >> !
> >> interface GigabitEthernet (WS-X6724-SFP)
> >>  dampening
> >>  mtu 4470
> >>  ip address xx.xx.xx.xx 255.255.255.252
> >>  carrier-delay msec 0
> >>  mpls traffic-eng tunnels
> >>  mpls ip
> >>  hold-queue 1000 in
> >>  ip rsvp bandwidth
> >> end
> >>
> >>
> >> 1.2. Marking of traffic occur on ingress interface of PE1
> >>
> >>>> policy-map test-in-dscp-set
> >>>> class class-default
> >>>> set dscp 39
> >> 2.3. Stock-taking dscp labels occur on ingress interface of PE2.
> >>
> >> -------------------------------------------------
> >> listing-------------------
> >>>> ping from CE
> >>>>      Type escape sequence to abort.
> >>>>      Sending 100, 100-byte ICMP Echos to 10.10.10.5, timeout is 2
> >> seconds:
> >>>>      Packet sent with a source address of 10.10.10.1
> >>>>      !!!!!
> >>>>      Success rate is 100 percent (100/100), round-trip min/avg/max =
> >> 1/4/9 ms
> >>>> PE2#sh policy-map interf Gi0/1.662 in class match-test-dscp
> >>>> GigabitEthernet0/1.662
> >>>>
> >>>> Service-policy input: Customer-test-In
> >>>>
> >>>> Class-map: match-test-dscp (match-any)
> >>>> 0 packets, 0 bytes
> >>>> 30 second offered rate 0 bps
> >>>> Match: ip dscp 39
> >>>> 0 packets, 0 bytes
> >>>> 30 second rate 0 bps
> >>>> ----------------- end of
> listing----------------------------------------
> >> As appears from an example marking do not occur
> >>
> >>
> >> 1.4 MPLS trace looks as follows
> >>
> >> PE1#trace mpls ipv4 213.xxx.xxx.4 255.255.255.255
> >> Tracing MPLS Label Switched Path to 213.xxx.xxx.4/32, timeout is 2
> seconds
> >>  Type escape sequence to abort.
> >>   0 213.xxx.xxx.202 MRU 4470 [Labels: 50 Exp: 0]
> >>  L 1 213.xxx.xxx.201 MRU 4474 [Labels: implicit-null Exp: 0] 169 ms
> >>  ! 2 213.xxx.xxx.18 4 ms
> >>
> >> PE1 encapsulate MPLS header to a package with value of the label = 50
> >> and a field
> >> Exp=0
> >>
> >> ==================================
> >>                                      The test #2
> >> ==================================
> >>
> >> The scheme of traffic's movement looks as  follows
> >>
> >>  CE--> SW-1> (ingress) PE1 (egress) --->(ingress)PE2
> >>
> >> 2.1 Device PE2 the last in the chain, it have PHP option enable by
> default
> >>
> >> MPLS trace looks as follows
> >> PE1#trace mpls ipv4 213.xxx.xxx.4 255.255.255.255
> >> Tracing MPLS Label Switched Path to 213.xxx.xxx.4/32, timeout is 2
> seconds
> >>  Type escape sequence to abort.
> >>   0 213.xxx.xxx.19 MRU 4470 [Labels: implicit-null Exp: 0]
> >>  ! 1 213.xxx.xxx.18 4 ms
> >>
> >> PE1 don't encapsulate MPLS header to a package.
> >> Result:
> >>
> >>>> PE2#sh policy-map interf Gi0/1.662 in class match-test-dscp
> >>>> GigabitEthernet0/1.662
> >>>>
> >>>> Service-policy input: Customer-test-In
> >>>>
> >>>> Class-map: match-test-dscp (match-any)
> >>>> 100 packets, 0 bytes
> >>>> 30 second offered rate 0 bps
> >>>> Match: ip dscp 39
> >>>> 100 packets, 0 bytes
> >>>> 30 second rate 0 bps
> >> So DSCP label comes on PE2
> >>
> >> 2.2 Device PE2 the last in a chain, option PHP switched off
> >>
> >> PE2 (config) # mpls ldp explicit-null
> >> PE2 (config) #
> >>
> >> So PE1 encapsulate MPLS header to a package,
> >> And as result packages again comes without DSCP label.
> >>
> >> Result.
> >> When MPLS label was encapsulated to header, as result DCSP label was
> >> cleared.
> >>
> >> Does anybody know decision for this problem?
> >>
> >>
> >> _______________________________________________
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> >>
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