[afnog] L2 channel errors

ibtisam jamal ibty.jamal at gmail.com
Fri Nov 4 08:27:32 UTC 2011


Hi ,

for this Ge PIC oversubscription 4:1 the utilization is actualy around
920Mbps ,and i can see the RED drops ,does this mean that the 1 Ge is
actualy working at around 800Mbps line rate ?

Regards,
Ibtisam



On Wed, Nov 2, 2011 at 10:32 PM, ibtisam jamal <ibty.jamal at gmail.com> wrote:

> Hi,
>
> Please see my response below...
>
>  On Wed, Nov 2, 2011 at 3:32 PM, Mark Tinka <mtinka at globaltransit.net>wrote:
>
>> On Wednesday, November 02, 2011 05:26:53 PM ibtisam jamal
>> wrote:
>>
>> > from 4 ge interfaces on one ge PIC...
>>
>> Sounds like you're talking about the 4-port Gig-E PIC. Just
>> not sure what Juniper platform you're talking about.>> Juniper m10i
>>
>>
>> > all 4 interfaces  show
>> > the errors ,while only 2 of them are configured as
>> > trunks the other 2 have only one vlan configured
>> > each.All the 4 interfaces have the L2 errors.Last night
>> > we tried to swap the PIC but today the same errors.
>>
>> The 4-port Gig-E PIC, both for the M7i/M10i as well as the
>> larger models, are oversubscribed 4:1. This means that
>> effectively, with all ports running at line rate, you can
>> only achieve 25% of 1Gbps on each port, as there is only a
>> 1Gbps connection to the PFE for that PIC.>>>is there a way to check this
>> 1Gbps connection utilization .
>>
> Would you know what these checksum errors mean and the discards.
>
>  @@@@@@@ show pfe statistics traffic
> Packet Forwarding Engine traffic statistics:
>     Input  packets:        2826536051484               398994 pps
>     Output packets:        2819386113592               398234 pps
> Packet Forwarding Engine local traffic statistics:
>     Local packets input                 :           3498362275
>     Local packets output                :           1091783398
>     Software input control plane drops  :                    0
>     Software input high drops           :                   26
>     Software input medium drops         :                18346
>     Software input low drops            :                    0
>     Software output drops               :                14650
>     Hardware input drops                :                 7816
> Packet Forwarding Engine local protocol statistics:
>     HDLC keepalives            :               464379
>     ATM OAM                    :                    0
>     Frame Relay LMI            :                    0
>     PPP LCP/NCP                :              1059990
>     OSPF hello                 :             20171430
>     OSPF3 hello                :                    0
>     RSVP hello                 :              8061634
>     LDP hello                  :                    0
>     BFD                        :            206871486
>     IS-IS IIH                  :                    0
>     LACP                       :                    0
>     ARP                        :           2151007242
>     ETHER OAM                  :                    0
>     Unknown                    :               162571
> Packet Forwarding Engine hardware discard statistics:
>     Timeout                    :                    0
>     Truncated key              :                    2
>     Bits to test               :                    0
>     Data error                 :                    0
>     Stack underflow            :                    0
>     Stack overflow             :                    0
>     Normal discard             :           4589614365
>     Extended discard           :                 5763
>     Invalid interface          :                    0
>     Info cell drops            :                    0
>     Fabric drops               :                    0
> Packet Forwarding Engine Input IPv4 Header Checksum Error and Output MTU
> Error statistics:
>     Input Checksum             :           8610737561
>     Output MTU                 :              5427563
>
>
>
>>
>> The reason I bring that up is I'm not quite familiar with
>> this PIC's architecture - I don't know whether the errors
>> you're seeing are reported for all ports, or for each port.>>>>>errors on
>> all ports on this PIC
>>
>>
>> You say that 2x of the ports are running 802.1Q. Please
>> confirm whether all VLAN's coming into the router from the
>> switch are present on both sides of the link.>>>>>>will confirm when i
>> get connection and get back to you.
>>
>>
>> Also, you mention that the other two remaining ports have
>> only one VLAN each, but no 802.1Q enabled. I don't see how
>> that's possible, as configurations of VLAN's on the PIC's
>> requires 802.1Q ('vlan-tagging' in Junos speak) to be
>> enabled. >>>yes vlan-tagging is enabled.
>>
>>
>> > We also see packet drops under the class-of-service
>>
>> I think let's look at that separately, in your e-mail on the
>> same, so we don't get the thread confused :-).
>>
>> Mark.
>>
>
>
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