IBM pSeries manual Nddipacketsmsw 0x00000000 Nddipacketslsw

Run the following command:

/usr/sbin/ifsn_dump -a

The data is collected in sni.snap (sni_dump.out.Z), and provides useful information, such as the local mac address:

mac_addr 0:0:0:40:0:0

If you are seeing arpq drops, ensure the source has the correct mac_addr for its destination.

The ndd statistics listed in ifsn_dump are useful for measuring packet drops in relation to the overall number of packets sent and received. ifsn_dump provides 64-bit counters for drops, sends, and receives, using msw and lsw 32-bit words. These 64-bit counters can be more useful than the 32-bit counters listed in netstat, because these 32-bit counters (limited to 4GB) can be quickly wrapped under heavy traffic loads on the switch.

Here is an example of ndd statistics listed by the ifsn_dump –acommand:

ndd_ipackets_msw	0x00000000 [0]
ndd_ipackets_lsw	0x00026357	[156503]
ndd_ibytes_msw	0x00000000	[0]
ndd_ibytes_lsw	0x012756be [19355326]
ndd_recvintr_msw	0x00000000	[0]
ndd_recvintr_lsw	0x00000000	[0]
ndd_ierrors	0x00000000	[0]
ndd_opackets_msw	0x00000000	[0]
ndd_opackets_lsw	0x00022595	[140693]
ndd_obytes_msw	0x00000000	[0]
ndd_obytes_lsw	0x01172099	[18292889]
ndd_xmitintr_msw	0x00000000	[0]
ndd_xmitintr_lsw	0x00000000	[0]
ndd_oerrors	0x00000000	[0]
ndd_nobufs	0x00000000	[0]
ndd_xmitque_max	0x00000000	[0]
ndd_xmitque_ovf	0x00000000	[0]
ndd_recvintr_msw	0x00000000	[0]
ndd_recvintr_lsw	0x00000000	[0]
ndd_ierrors	0x00000000	[0]
ndd_opackets_msw	0x00000000	[0]
ndd_opackets_lsw	0x00022595	[140693]
ndd_obytes_msw	0x00000000	[0]
ndd_obytes_lsw	0x01172099	[18292889]
ndd_xmitintr_msw	0x00000000	[0]
ndd_xmitintr_lsw	0x00000000	[0]
ndd_oerrors	0x00000000	[0]
ndd_nobufs	0x00000000	[0]
ndd_xmitque_max	0x00000000	[0]
ndd_xmitque_ovf	0x00000000	[0]
ndd_ipackets_drop	0x00000000	[0]
ndd_ibadpackets	0x00000000	[0]
ndd_opackets_drop	0x00000000	[0]
ndd_xmitque_cur	0x00000000	[0]
ndd_ifOutUcastPkts_msw 0x00000000 [0]
ndd_ifOutUcastPkts_lsw 0x00020e67 [134759]
ndd_ifOutMcastPkts_msw 0x00000000 [0]
ndd_ifOutMcastPkts_lsw 0x00000000 [0]
ndd_ifOutBcastPkts_msw 0x00000000 [0]
ndd_ifOutBcastPkts_lsw 0x0000172e [5934]

pshpstuningguidewp040105.doc Page 25