[c-nsp] Input Queue 7500

[omar parihuana]

Thanks Anton for your reply.

CEF is enable (ip cef global configuration command is configured):

R#show interfaces switching
FastEthernet4/1/0
          Throttle count          8
        Drops         RP        491         SP          0
  SPD Flushes       Fast       2561        SSE          0
  SPD Aggress       Fast          0
 SPD Priority     Inputs          0      Drops          0

     Protocol       Path    Pkts In   Chars In   Pkts Out  Chars Out
        Other    Process          0          0     436870   26212200
            Cache misses          0
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0
           IP    Process 2226190620 2002650219 2393235708 2822177457
            Cache misses        623
                    Fast 1763768067  234570619 1779057481 4136533720
               Auton/SSE          0          0          0          0
      DEC MOP    Process          0          0       7270     559790
            Cache misses          0
                    Fast          0          0          0          0
               Auton/SSE          0          0          0          0

Also, I enable ip route-cache flow in this interface because there is a long
access-list (in accordance to suggestion the previous link -the drops and
flash increase slower than without the ip route-cache flow) Currently the
7513 is attached to Black Box (Allied Telesin Switch, that unfortunately, I
don't have admin) is possible that Allied Telesin Switch cause this input
queue drops, because the low performance of Allied, sometimes the CPU
processor reach 80% too.

7513-118.1#sh cef drop
CEF Drop Statistics
Slot  Encap_fail  Unresolved Unsupported    No_route      No_adj  ChkSum_Err
RP          3747           0         656          32           0           0
7513-118.1#

So far, unfortunately, the counter is increasing...

Input queue: 56/75/247/178 (size/max/drops/flushes); Total output drops: 0

Thanks!!

Rgds.


On 12/27/06, Anton Kapela <tk at 5ninesdata.com> wrote:
>
>
>
> > I've noticed the input queue interface ethernet from my 7513
> > (drops and flushes is increasing)
>
> That counter doesn't mean what Cisco lets you think it means....
>
> >  Encapsulation ARPA, loopback not set
> >   Keepalive set (10 sec)
> >   Full-duplex, 100Mb/s, 100BaseTX/FX
> >   ARP type: ARPA, ARP Timeout 04:00:00
> >   Last input 00:00:00, output 00:00:00, output hang never
> >   Last clearing of "show interface" counters 00:35:20
> >   Input queue: 5/75/1053/6148 (size/max/drops/flushes); Total
> > output drops:
> > 0   <<<<< SEE HERE!
>
> > This behavior is normal, for that traffic (About 45Mbps in
> > some cases) ???
>
> That should not be observed unless you're: running cef-less, being
> directly attacked, or attached to noisy-ass layer-2 that faces, oh, say,
> a few thousand collocation customers with 50 or 60 ip address
> secondary's configured. Any of those situations could be causing what
> you're seeing, and let me be clear: none of them would be characterized
> as normal.
>
> > How can I decrease that counters? some suggestions for set up
> > in Ethernet Interface???
>
> First of all, 'sh int' input queue is a depiction of the state of
> packets which were placed into queue for the "ip_input" process; i.e.
> these are packets waiting to be "process switched." This is generally
> bad. Before you go any further in troubleshooting this, check to ensure
> that cef is enabled on your router.
>
> If it is, then start debugging and checking your switching path. You can
> do this by becoming more familiar with the 7500 switching architecture.
> I'd suggest the following URLs to get yourself started:
>
> 1)      http://tinyurl.com/7fw4p
>
> Be sure to focus on this part of the page:
>
> 2)      http://tinyurl.com/wg8qz
>
>
> Also, use the following commands on interfaces which you're seeing the
> input queue drops on:
>
> #sh int FastEthernet3/0/0 switching
>
> #sh int FastEthernet3/0/0 stats
>
> #sh int FastEthernet3/0/0 accounting
>
> In a nutshell, when you see actual ip_input queue drops (which is what
> the 'sh int' is displaying), things are "not good."
>
> Any protocol which requires RSP/RP attention must be punted to the host
> processor. This includes stuff like certain layer-2 ethertype
> broadcasts, ARP, BFD, OSPF Hellos, certain other multicast, DHCP, and
> CDP, in addition to packets directly addressed to the routers interfaces
> or control plane. If cef is disabled entirely on your box, then this
> counter will be including buffered packets about to be switched, which
> it normally (when cef is running) would not.
>
> You can get a feel for what protocol 'groups' are listening (read:
> configuring cef to punt packets up to the host rsp/rp) on an interface
> by looking at the routers hardware & software IDB allocation. To see it,
> use:
>
> #sh idb
>
> [snip]
>
> HWIDB#1   Serial1/0/0:1 (HW IFINDEX(10001), HW SB CDP(4), Serial(3), MAC
> ADDR(1))
> HWIDB#2   Serial1/0/0:2 (HW IFINDEX(10001), HW SB CDP(4), Serial(3), MAC
> ADDR(1))
> HWIDB#3   Serial1/0/0:3 (HW IFINDEX(10001), HW SB CDP(4), Serial(3), MAC
> ADDR(1))
> [snip]
>
> SWIDB#1   Serial1/0/0:1 (SW CDP(4), NetBIOS(2), DSS(3), KEEPALIVE(1))
> SWIDB#2   Serial1/0/0:2 (SW CDP(4), NetBIOS(2), DSS(3), KEEPALIVE(1))
> SWIDB#3   Serial1/0/0:3 (SW CDP(4), NetBIOS(2), DSS(3), KEEPALIVE(1))
> [snip]
>
> Good luck,
>
> -Tk
>



-- 
Omar E.P.T
-----------------
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http://omarept.blogspot.com/

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