From: David Duncon (david_ccie@hotmail.com)
Date: Thu Aug 05 2004 - 03:36:51 GMT-3
Hi Chuck,
Good advise. Never had to manipulate buffers though on production networks
since last couple of years. And always worked on default values with out any
issues. Even we have several 2651MXs with similar code and memory on several
other LAN sites on WAN with exactly the same config, but we only had this
issue on this guy.
As we have already deployed "ip cef" which is happily working on dot1q
trunks at the moment and also since we got more than 2MB of memory and the
CPU is historically sitting at around 40% mark, I think I can afford to
deploy some extra buffers as you suggested.
As I need to go through a regimental CCR (change control request) gates , I
will be aiming to implement your suggestion with in a week or so.
I will unicast you the results.
Once again , Thanks for your time :-)
David.
>From: "Church, Chuck" <cchurch@netcogov.com>
>To: "David Duncon" <david_ccie@hotmail.com>, <ccielab@groupstudy.com>
>Subject: RE: High Ignored Packet Errors
>Date: Wed, 4 Aug 2004 06:52:22 -0500
>
>It looks like it's taking a beating. First off, enable CEF if it isn't
>already. 'Ip cef' from global config should do it. See if that helps.
>I think 12.2 does CEF for dot1q trunks. At one time, only ISL could do
>CEF. Do a sh ip int to verify the subints. See if that helps at all.
>If not, or CEF is already enabled, add this:
>Buf small per 100
>Buf mid per 100
>Buf big per 75
>Buf very per 15
>Buf lar per 10
>Buf huge per 10
>
>This assumes that you're not real low on memory (do a sh mem, look at
>first couple lines, make sure proc mem is over a couple megs free) and
>that your CPU isn't averaging over 70% (sh proc cpu hist). These deeper
>buffer queues will force packets to stay a little longer in the router,
>but for most traffic (like TCP), a few millisecond delay is better than
>a drop and retransmit. Keep in mind that a 2651XM, while on the beefy
>side of the 2600s, still can't come close to forwarding 100mb at
>linerate. HTH.
>
>
>Chuck Church
>Wam!Net Government Services - D&I Team
>Lead Design Engineer
>CCIE #8776, MCNE, MCSE
>1210 N. Parker Rd.
>Greenville, SC 29609
>Office: 864-335-9473
>Cell: 703-819-3495
>cchurch@wamnetgov.com
>PGP key:
>http://pgp.mit.edu:11371/pks/lookup?op=index&search=cchurch%40wamnetgov.
>com
>
>-----Original Message-----
>From: David Duncon [mailto:david_ccie@hotmail.com]
>Sent: Wednesday, August 04, 2004 1:19 AM
>To: Church, Chuck; ccielab@groupstudy.com
>Subject: RE: High Ignored Packet Errors
>
>Thanks for your response , Chuck.
>
>Here are my "sh buffers" and "sh run int fa0/0" outputs.
>
>
>Router01#sh buffers
>Buffer elements:
> 998 in free list (500 max allowed)
> 2727789782 hits, 0 misses, 500 created
>
>Public buffer pools:
>Small buffers, 104 bytes (total 50, permanent 50, peak 185 @ 2w4d):
> 45 in free list (20 min, 150 max allowed)
> 1376927835 hits, 17724 misses, 6045 trims, 6045 created
> 7429 failures (0 no memory)
>Middle buffers, 600 bytes (total 25, permanent 25, peak 196 @ 7w0d):
> 23 in free list (10 min, 150 max allowed)
> 990639003 hits, 596896 misses, 1724 trims, 1724 created
> 493890 failures (0 no memory)
>Big buffers, 1536 bytes (total 50, permanent 50, peak 77 @ 2w4d):
> 50 in free list (5 min, 150 max allowed)
> 12327055 hits, 483387 misses, 49 trims, 49 created
> 482393 failures (0 no memory)
>VeryBig buffers, 4520 bytes (total 10, permanent 10, peak 15 @ 2w4d):
> 10 in free list (0 min, 100 max allowed)
> 3798 hits, 481824 misses, 9 trims, 9 created
> 481824 failures (0 no memory)
>Large buffers, 5024 bytes (total 1, permanent 0, peak 7 @ 2w4d):
> 1 in free list (0 min, 10 max allowed)
> 208 hits, 481722 misses, 3433 trims, 3434 created
> 481722 failures (0 no memory)
>Huge buffers, 18024 bytes (total 1, permanent 0, peak 13 @ 7w0d):
> 1 in free list (0 min, 4 max allowed)
> 5384 hits, 481673 misses, 3473 trims, 3474 created
> 481651 failures (0 no memory)
>
>Interface buffer pools:
>CD2430 I/O buffers, 1536 bytes (total 0, permanent 0):
> 0 in free list (0 min, 0 max allowed)
> 0 hits, 0 fallbacks
>
>Header pools:
>Header buffers, 0 bytes (total 434, permanent 128, peak 434 @ 7w0d):
> 306 in free list (10 min, 512 max allowed)
> 39121 hits, 268 misses, 0 trims, 306 created
> 29 failures (0 no memory)
> 128 max cache size, 128 in cache
> 2684203733 hits in cache, 39025 misses in cache
>
>Particle Clones:
> 1024 clones, 807290403 hits, 0 misses
>
>Public particle pools:
>F/S buffers, 256 bytes (total 384, permanent 384):
> 128 in free list (128 min, 1024 max allowed)
> 256 hits, 0 misses, 0 trims, 0 created
> 0 failures (0 no memory)
> 256 max cache size, 256 in cache
> 1602224646 hits in cache, 0 misses in cache Normal buffers, 1548
>bytes (total 512, permanent 512):
> 368 in free list (128 min, 1024 max allowed)
> 304304773 hits, 605 misses, 126 trims, 126 created
> 1 failures (0 no memory)
> 128 max cache size, 128 in cache
> 0 hits in cache, 0 misses in cache
>
>Private particle pools:
>FastEthernet0/0 buffers, 1548 bytes (total 192, permanent 192):
> 0 in free list (0 min, 192 max allowed)
> 192 hits, 0 fallbacks
> 192 max cache size, 128 in cache
> 1050384350 hits in cache, 1657494 misses in cache
>FastEthernet0/1 buffers, 1548 bytes (total 192, permanent 192):
> 0 in free list (0 min, 192 max allowed)
> 192 hits, 0 fallbacks
> 192 max cache size, 128 in cache
> 1683380742 hits in cache, 282 misses in cache Serial0/0 buffers,
>1548 bytes (total 32, permanent 32):
> 0 in free list (0 min, 32 max allowed)
> 32 hits, 0 fallbacks
> 32 max cache size, 16 in cache
> 2648556287 hits in cache, 302646710 misses in cache
>Serial0/1 buffers, 1548 bytes (total 32, permanent 32):
> 0 in free list (0 min, 32 max allowed)
> 32 hits, 0 fallbacks
> 32 max cache size, 32 in cache
> 0 hits in cache, 0 misses in cache
>.......................................................................
>................................
>
>Router01#sh run int fa0/0
>Building configuration...
>
>Current configuration : 90 bytes
>!
>interface FastEthernet0/0
>no ip address
>load-interval 30
>speed 100
>full-duplex
>end
>.......................................................................
>..............................
>Router01#sh run int fa0/0.2
>Building configuration...
>
>Current configuration : 491 bytes
>!
>interface FastEthernet0/0.2
>encapsulation dot1Q 2
>ip address 10.3.1.2 255.255.254.0
>standby 2 ip 10.3.1.1
>standby 2 timers 1 4
>standby 2 priority 110
>standby 2 preempt
>standby 2 track Serial0/0.200 40
>
>
>Router01#sh run int fa0/0.3
>Building configuration...
>
>Current configuration : 321 bytes
>!
>interface FastEthernet0/0.3
>encapsulation dot1Q 3
>ip address 10.3.7.2 255.255.255.0
>standby 2 ip 10.3.7.1
>standby 3 timers 1 4
>standby 3 priority 110
>standby 3 preempt
>standby 3 track Serial0/0.200 40
>end
>
>Router01#sh run int fa0/0.4
>Building configuration...
>
>Current configuration : 321 bytes
>!
>interface FastEthernet0/0.4
>encapsulation dot1Q 4
>ip address 10.3.2.2 255.255.255.0
>standby 2 ip 10.3.2.1
>standby 4 timers 1 4
>standby 4 priority 110
>standby 4 preempt
>standby 4 track Serial0/0.200 40
>end
>
>David.
>
>
> >From: "Church, Chuck" <cchurch@netcogov.com>
> >To: "David Duncon" <david_ccie@hotmail.com>, <ccielab@groupstudy.com>
> >Subject: RE: High Ignored Packet Errors
> >Date: Tue, 3 Aug 2004 08:49:45 -0500
> >
> >From CCO:
> >
> >"Ignored Packets
> >
> >router#show interfaces ethernet 0
> >Ethernet0/0 is up, line protocol is up
> >..
> > 21 input errors, 0 CRC, 0 frame, 0 overrun, 21 ignored
> >
> >Packets are ignored if there are no free buffers to accept the new
> >packet. This can happen if the router is overloaded with traffic, but
> >can also happen if the interface is faulty. If "ignores" are present on
>
> >all interfaces, then the router is probably overloaded with traffic, or
>
> >doesn't have sufficient free buffers in the pool that match the maximum
>
> >transmission unit (MTU) on interfaces. In the latter case, an increment
>
> >of the ignored counter is followed by an increment of the no buffer
> >counter:"
> >
> >What does 'sh buf' tell you? And what's your config look like for this
>
> >ethernet interface?
> >
> >
> >Chuck Church
> >Wam!Net Government Services - D&I Team
> >Lead Design Engineer
> >CCIE #8776, MCNE, MCSE
> >1210 N. Parker Rd.
> >Greenville, SC 29609
> >Office: 864-335-9473
> >Cell: 703-819-3495
> >cchurch@wamnetgov.com
> >PGP key:
> >http://pgp.mit.edu:11371/pks/lookup?op=index&search=cchurch%40wamnetgov
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