IBM pSeries manual Packets dropped in the ML0 interface

To help you isolate the exact cause of packet drops, the ifsn_dump -acommand also lists the following debug statistics. If you isolate packet drops to these statistics, you will probably need to contact IBM support.

dbg:

sNet_drop	0x00000000	[0]
sRTF_drop	0x00000000	[0]
sMbuf_drop	0x00000000	[0]
sFifo_drop	0x00000000	[0]
sQueue_drop	0x00000000	[0]
rPool_drop	0x00000000	[0]
m_reject	0x00000000	[0]
rsvd_pool_used	0x00000000	[0]
recv_not_ready	0x00000000	[0]
recv_bad_flag	0x00000000	[0]
recv_bad_type	0x00000000	[0]
alloc_cntl_fail	0x00000000	[0]
spkt_timeout	0x00000000	[0]
bad_health_drop	0x00000000	[0]
phantom_recv_intr	0x00000000	[0]
same_thresh_cnt	0x00000000	[0]
last_recv_thresh	0x0000000000000000 [0]

To see some packet drops (such as arpq drops), you must use the kdb ifnet structure (which is common for many interfaces). Here is an example:

echo ifnet kdb[ . . .			]
SLOT	2 ----	IFNET INFO		----(@ 075AF098)----
name		sn0		unit	00000000	mtu	0000FFE0
flags		08800843
	(UPBROADCASTRUNNINGSIMPLEXNOECHOBPFIFBUFMGTCANTCHANGE...
[. . .	]
init()	......	00000000 output()....			075AE498 start()		00000000
done()	......	00000000 ioctl()			075AE4B0 reset()		00000000
watchdog()..		00000000 ipackets....			00026549 ierrors		00000000
opackets....		00022778 oerrors			00000000 collisions.. 00000000
next		075AF2C8		type	00000038	addrlen	00000000
hdrlen		00000018		index	00000003
ibytes		0127BA9E		obytes	0117B005	imcasts	00000000
omcasts		00000000		iqdrops	00000000	noproto	00000000
baudrate....		00000000		arpdrops....	00000002	ifbufminsize 00000200
devno		8000002300000000 chan				2FF38EB0 multiaddrs..		00000000
tap()		00000000		tapctl	FFFFFFFFFFFFFFFF arpres()....			00000000
arprev()....		00000000		arpinput()	.. 00000000	ifq_head....	00000000
ifq_tail....		00000000		ifq_len	00000000	ifq_maxlen.. 00000200
ifq_drops...		00000000		ifq_slock...	00000000	slock	00000000

5.12.2 Packets dropped in the ML0 interface

For ml0 drops to a destination, use the mltdd_dump -kcommand to determine if a valid ml0 route exists to destination:

/usr/sbin/mltdd_dump -k

The following example shows the route to ml0 destination 192.168.2.3, which is a valid and complete ml0 route. If a route is incomplete, it is not valid.

mlr_next = 0x0000000000000000 mlr.state = 160

(COMPLETE)

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